Optical analyzer assembly with safety shutdown system for intravascular lithotripsy device - Patent Application 20070122997

Abstract

A suitable catheter system is provided for treating treatment sites within or adjacent to a blood vessel wall or heart valve. The catheter system (200) includes a light source (224), a balloon (104), a light guide (222A), and an optical analyzer assembly (242). The light source (224) generates first light energy. The balloon (104) is positionable substantially adjacent to a treatment site and has a balloon wall defining a balloon interior that receives a balloon fluid. The light guide (222A) receives the first light energy and guides the first light energy in a first direction from a guide proximal end positioned within the balloon interior toward a guide distal end. The optical analyzer assembly (242) optically analyzes second light energy from the light guide (222A) traveling in a second direction opposite the first direction.

Description

[Technical Field]

[0001] Related Applications This application is related to and claims priority to U.S. Provisional Patent Application No. 63 / 186,391, filed May 10, 2021, and U.S. Patent Application No. 17 / 736,894, filed May 4, 2022. To the extent permitted, the contents of U.S. Provisional Patent Application No. 63 / 186,391 and U.S. Patent Application No. 17 / 736,894 are incorporated herein by reference in their entireties. [Background technology]

[0002] Vascular lesions within the body's blood vessels can be associated with an increased risk of major adverse events such as myocardial infarction, embolism, deep vein thrombosis, stroke, etc. Severe vascular lesions can be difficult to treat and physicians may have difficulty achieving patency in clinical practice.

[0003] Vascular lesions can be treated using interventions such as drug therapy, balloon angioplasty, atherectomy, stent placement, vascular graft bypass, to name a few, but such interventions may not always be ideal or may require subsequent treatment to address the lesion. Summary of the Invention

[0004] The present invention relates to a catheter system for treating a treatment site within or adjacent to a blood vessel wall or heart valve. In various embodiments, the catheter system includes a light source, a balloon, a light guide, and an optical analyzer assembly. The light source generates a first light energy. The balloon is positionable substantially adjacent to the treatment site. The balloon has a balloon wall defining a balloon interior that receives a balloon fluid. The light guide is configured to receive the first light energy at a proximal end and guide the first light energy in a first direction from the proximal end toward a distal end positioned within the balloon interior. The optical analyzer assembly is configured to optically analyze second light energy from the light guide traveling in a second direction opposite the first direction. The optical analyzer assembly includes a safety shutdown system that is selectively activated to prevent the first light energy from the light source from being received by the proximal end of the light guide.

[0005] In some embodiments, the catheter system further includes a pulse generator coupled to the light source, the pulse generator being configured to trigger the light source to generate a light source beam that is directed toward the light guide.

[0006] In certain embodiments, the safety shutdown system includes a safety interlock that is selectively activated to prevent the pulse generator from triggering generation of the source beam with the light source.

[0007] In various embodiments, the safety shutdown system includes a shutter that is selectively actuated to prevent the light source beam from being directed toward the light guide.

[0008] In some embodiments, the first light energy induces the generation of plasma within the interior of the balloon.

[0009] In certain embodiments, the guide distal end includes a distal light receiver that receives second light energy from within the balloon interior, the second light energy traveling in a second direction through the light guide.

[0010] In some embodiments, the second light energy received by the distal light receiver is emitted from a plasma generated in the balloon fluid within the interior of the balloon.

[0011] In certain embodiments, the second light energy received by the distal light receiver is from ambient light near the distal guide end of the light guide.

[0012] In various embodiments, the second optical energy received by the distal optical receiver is optically analyzed by an optical analyzer assembly.

[0013] In some embodiments, the optical analyzer assembly is configured to optically determine whether plasma generation within the interior of the balloon has occurred within the interior of the balloon.

[0014] In certain embodiments, the optical analyzer assembly is configured to optically detect faults in the light guide between the proximal guide end and the distal guide end.

[0015] In some embodiments, the optical analyzer assembly is configured to optically detect potential damage to the light guide between the proximal guide end and the distal guide end.

[0016] In many embodiments, the optical analyzer assembly is configured to selectively activate a safety shutdown system upon optical detection by the optical analyzer assembly of any one of (i) failure to generate plasma within the balloon interior, (ii) failure of the optical guide between the proximal guide end and the distal guide end, and (iii) potential damage to the optical guide between the proximal guide end and the distal guide end.

[0017] In some embodiments, the second light energy is guided back through the light guide in a second direction toward the proximal end of the guide. The optical analyzer assembly is configured to optically analyze the second light energy to determine whether plasma generation has occurred within the balloon interior.

[0018] In certain embodiments, the optical analyzer assembly includes a beam splitter and a photodetector, the beam splitter configured to receive the second light energy and direct a portion of the second light energy to the photodetector.

[0019] In some embodiments, the optical analyzer assembly further includes an optical element positioned along the beam path between the beam splitter and the photodetector, the optical element configured to couple a portion of the second light energy to the photodetector.

[0020] In certain embodiments, the optical analyzer assembly may further include a second beam splitter positioned along the beam path between the beam splitter and the photodetector, the second beam splitter configured to receive the second optical energy and direct at least a portion of the second optical energy to the photodetector.

[0021] In some embodiments, the photodetector generates a signal based at least in part on visible light contained in the portion of the second light energy.

[0022] In certain embodiments, the signal from the photodetector is amplified with an amplifier to provide an amplified signal that is directed to control electronics to determine the intensity of the plasma generation within the balloon interior.

[0023] In some embodiments, the control electronics are configured to analyze the amplified signal to detect one or more of: (i) whether plasma generation has occurred within the balloon interior; (ii) potential failure of the light guide between the proximal guide end and the distal guide end; and (iii) potential damage to the light guide between the proximal guide end and the distal guide end.

[0024] In various embodiments, the optical analyzer is configured to optically analyze the second light energy to detect an operating condition of the catheter system.

[0025] In some embodiments, the optical analyzer is configured to optically analyze the second light energy to detect at least one of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a poor plasma generation condition, (v) a broken light guide condition, and (vi) a chewback condition.

[0026] In other embodiments, the optical analyzer is configured to optically analyze the second light energy to detect at least two of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition.

[0027] In yet another embodiment, the optical analyzer is configured to optically analyze the second light energy to detect at least three of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition.

[0028] In yet another embodiment, the optical analyzer is configured to optically analyze the second light energy to detect at least four of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition.

[0029] In yet another embodiment, the optical analyzer is configured to optically analyze the second light energy to detect at least five of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition.

[0030] In yet another embodiment, the optical analyzer is configured to optically analyze the second light energy to detect each of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a poor plasma generation condition, (v) a broken light guide condition, and (vi) a chewback condition.

[0031] In some embodiments, the optical analyzer assembly can be further configured to stop operation of the catheter system upon detecting one or more of a poor plasma generation condition, a broken light guide condition, and a chewback condition.

[0032] In certain embodiments, a first pulse of light energy directed in a first direction through the light guide generates a plasma flash that can be captured by the optical analyzer assembly in the form of a flash signature that can include summary parameters such as at least one of pulse maximum, rise time, width, onset time relative to a baseline, and a measure of signal variability, which can provide an indication of the operating condition of the catheter system.

[0033] In some embodiments, if the pulse maximum of the flash signature is greater than a maximum pulse maximum threshold, the optical analyzer assembly can identify the operating condition as a guide distal end plasma initiation condition.

[0034] In certain embodiments, if the pulse maximum value of the flash signature is less than the minimum pulse maximum threshold, the optical analyzer assembly can identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition.

[0035] In some embodiments, the optical analyzer assembly is configured to require the number of pulses of first light energy in which the pulse maximum of the flash signature is less than a minimum pulse maximum threshold within a specified range of previous pulses to exceed a defined zero pulse count in order to identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition.

[0036] In certain embodiments, the history of all pulses of first light energy directed in a first direction through the light guide is tracked to distinguish between intermittent bubble generation conditions, poor plasma generation conditions, and broken light guide conditions.

[0037] In some embodiments, the measure of signal variability of the flash signature comprises the number of transitions identified in the flash signature.

[0038] In certain embodiments, if the number of transitions in the flash signature is greater than a transition threshold, the optical analyzer assembly can identify the operating condition as a Chewback condition.

[0039] In many embodiments, the guide distal end includes a distal light receiver that receives second light energy from within the balloon interior, the second light energy traveling in a second direction through the light guide.

[0040] In some embodiments, the second light energy received by the distal light receiver is from ambient light near the distal guide end of the light guide.

[0041] In certain embodiments, the optical analyzer assembly is configured to optically analyze the second light energy to determine whether ambient light is collected near the guide distal end of the light guide.

[0042] In some embodiments, the optical analyzer assembly includes a beam splitter and an imaging device, the beam splitter configured to receive the second light energy and direct a portion of the second light energy to the imaging device.

[0043] In certain embodiments, the optical analyzer assembly further includes an optical element positioned along the beam path between the beam splitter and the imaging device, the optical element configured to couple a portion of the second light energy to the imaging device.

[0044] In some embodiments, the optical analyzer assembly further includes a second beam splitter positioned along the beam path between the beam splitter and the imaging device, the second beam splitter configured to receive the second optical energy and direct at least a portion of the second optical energy onto the imaging device.

[0045] In certain embodiments, the imager generates a signal based at least in part on any ambient light included in the portion of the second light energy.

[0046] In some embodiments, a signal from the imaging device is directed to control electronics to determine whether ambient light is collected near the distal guide end of the light guide.

[0047] In certain embodiments, a determination by the control electronics that ambient light is collected near the distal guide end of the light guide is an indication that the catheter system is being used in an improper manner, with the balloon not positioned substantially adjacent to the treatment site.

[0048] In various embodiments, the light source includes a laser.

[0049] In some embodiments, the light source includes an infrared laser that emits the first light energy in the form of pulses of infrared light.

[0050] In many embodiments, the light guide comprises an optical fiber.

[0051] The present invention is further directed to a method of treating a treatment site within or adjacent a blood vessel wall or heart valve, the method comprising: generating first light energy using a light source; positioning a balloon substantially adjacent the treatment site, the balloon having a balloon wall defining a balloon interior that receives a balloon fluid; receiving the first light energy at a proximal guide end of a light guide; guiding the first light energy in a first direction from the proximal guide end toward a distal guide end positioned within the balloon; and optically analyzing second light energy from the light guide traveling in a second direction opposite the first direction, wherein the optical analyzer assembly includes a safety shutdown system selectively activated to prevent the first light energy from the light source from being received by the proximal guide end of the light guide.

[0052] The present invention is also directed to a catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, the catheter system comprising: a light source that generates a first light energy; a balloon positionable substantially adjacent to the treatment site, the balloon having a balloon wall defining a balloon interior that receives a balloon fluid; a light guide configured to receive the first light energy at a proximal guide end and guide the first light energy in a first direction from the proximal guide end toward a distal guide end positioned within the balloon; and an optical analyzer assembly configured to optically analyze second light energy from the light guide traveling in a second direction opposite the first direction, the optical analyzer configured to optically analyze the second light energy to detect an operational status of the catheter system.

[0053] The present invention is further directed to a method of treating a treatment site within or adjacent to a blood vessel wall or heart valve, the method including generating first light energy using a light source; positioning a balloon substantially adjacent to the treatment site, the balloon having a balloon wall defining a balloon interior that receives a balloon fluid; receiving the first light energy at a proximal guide end of a light guide; guiding the first light energy in a first direction from the proximal guide end toward a distal guide end positioned within the balloon; and optically analyzing second light energy from the light guide traveling in a second direction opposite the first direction, wherein the optical analyzer is configured to optically analyze the second light energy to detect an operating status of the catheter system.

[0054] This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are found in the detailed description and appended claims. Other aspects will be apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which is not to be construed in a limiting sense. The scope of the present specification is defined by the appended claims and their legal equivalents.

[0055] The novel features of the present invention, as well as the invention itself, both as to its structure and its operation, will best be understood from the accompanying drawings taken in conjunction with the accompanying description, in which like reference numerals refer to like parts, and in which: [Brief explanation of the drawings]

[0056] [Figure 1] 1 is a schematic cross-sectional view of one embodiment of a catheter system including an optical analyzer assembly having features of the present invention, in accordance with various embodiments herein. [Figure 2A] 1 is a simplified schematic diagram of a portion of an embodiment of a catheter system including an embodiment of an optical analyzer assembly utilized in a first application. [Figure 2B] FIG. 2B is a simplified schematic diagram of a portion of a catheter system including the optical analyzer assembly of FIG. 2A utilized in a second application. [Figure 3A] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 3B] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 3C] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 3D] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 3E] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 3F] 2 is a simplified schematic diagram of operating conditions that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. FIG. [Figure 4A] FIG. 2 is a simplified graphical representation of a representative example of one flash signature that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. [Figure 4B] FIG. 2 is a simplified graphical representation of a representative example of a second different flash signature that may be identified by the optical analyzer assembly during operation of the catheter system of FIG. 1. [Figure 5] FIG. 2 is a simplified graphical illustration of an example of a pulse maximum reading that may be identified by an optical analyzer assembly when a first pulse of light energy is sent through a light guide used in the catheter system of FIG. 1. [Figure 6] FIG. 2 is a simplified graphical representation of an example of the number of transitions that may be identified by an optical analyzer assembly in a flash signal generated when a first pulse of light energy is sent through a light guide used in the catheter system of FIG. 1. [Figure 7] FIG. 2 is a simplified graphical illustration of one example of how a no signal detection condition may be identified by an optical analyzer assembly when a first pulse of light energy is sent through a light guide used in the catheter system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0057] While embodiments of the invention are susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example and in the drawings and are herein described in detail. It is understood, however, that the scope of the specification is not limited to the particular embodiments described. On the contrary, the intent is to cover modifications, equivalents, and alternatives falling within the spirit and scope of the specification.

[0058] Treating vascular lesions (sometimes referred to herein as "treatment sites") can reduce major adverse events or deaths in affected subjects. As referred to herein, a major adverse event is an adverse event that can occur anywhere in the body due to the presence of a vascular lesion. Major adverse events can include, but are not limited to, major adverse cardiac events, major adverse events in the peripheral or central vascular system, major adverse events in the brain, major adverse events in the muscular system, or major adverse events in any of the internal organs.

[0059] As used herein, the terms "intravascular lesion," "vascular lesion," and "treatment site" are used interchangeably unless otherwise specified. Intravascular lesions and / or vascular lesions may be referred to herein simply as "lesions."

[0060] Those skilled in the art will realize that the following detailed description of the invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled artisans having the benefit of this disclosure. Reference will now be made in detail to embodiments of the invention as illustrated in the accompanying drawings.

[0061] For clarity, not all of the routine features of the embodiments described herein are shown and described. It will, of course, be understood that the development of any such actual implementation requires many implementation-specific decisions to be made in order to achieve the developer's particular goals, such as compliance with application- and business-related constraints, and that these particular goals will vary from implementation to implementation and from developer to developer. Moreover, it will be understood that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.

[0062] The catheter systems disclosed herein can include many different configurations. Referring now to FIG. 1 , a schematic cross-sectional view of a catheter system 100 according to various embodiments is shown. The catheter system 100 is suitable for applying pressure waves to induce fracture at one or more treatment sites within a patient's body, within or adjacent to a blood vessel wall, or on or adjacent to a heart valve. In the embodiment shown in FIG. 1 , the catheter system 100 includes one or more of a catheter 102, a light guide bundle 122 including one or more light guides 122A, a source manifold 136, a fluid pump 138, a system console 123 including one or more of a light source 124, a power supply 125, a system controller 126, and a graphic user interface 127 (“GUI”), a handle assembly 128, and an optical analyzer assembly 142. Alternatively, the catheter system 100 can include more or fewer components than those specifically shown and described in connection with FIG. 1 .

[0063] Although the catheter system 100 is generally described as including a light guide bundle 122 including one or more light guides 122A and a light source 124, it is understood that in some alternative embodiments, the catheter system 100 can include an energy guide bundle including different types of energy guides and / or different types of energy sources.

[0064] In various embodiments, the catheter 102 is configured to navigate to a treatment site 106 within or adjacent to a vascular wall 108A of a blood vessel 108 within the body 107 of the patient 109. The treatment site 106 may include one or more vascular lesions 106A, such as, for example, a calcified vascular lesion. Additionally or alternatively, the treatment site 106 may include a vascular lesion 106A, such as a fibrous vascular lesion. Further alternatively, in some implementations, the catheter 102 may be used at a treatment site 106 within or adjacent to a heart valve within the body 107 of the patient 109.

[0065] The catheter 102 may include an inflatable balloon 104 (sometimes referred to herein simply as a "balloon"), a catheter shaft 110, and a guidewire 112. The balloon 104 may be coupled to the catheter shaft 110. The balloon 104 may include a balloon proximal end 104P and a balloon distal end 104D. The catheter shaft 110 may extend from a proximal portion 114 of the catheter system 100 to a distal portion 116 of the catheter system 100. The catheter shaft 110 may include a longitudinal axis 144. The catheter shaft 110 may also include a guidewire lumen 118 configured to travel over the guidewire 112. As utilized herein, the guidewire lumen 118 defines a conduit through which the guidewire 112 extends. The catheter shaft 110 may further include an inflation lumen (not shown) and / or various other lumens for various other purposes. In some embodiments, the catheter 102 can have a distal end opening 120 that can accommodate and pass over a guidewire 112 as the catheter 102 is moved and positioned at or near the treatment site 106. In some embodiments, the balloon proximal end 104P can be coupled to the catheter shaft 110, and the balloon distal end 104D can be coupled to the guidewire lumen 118.

[0066] The balloon 104 includes a balloon wall 130 that defines a balloon interior 146. The balloon 104 can be selectively inflated with a balloon fluid 132 to expand from a deflated state suitable for advancing the catheter 102 through a patient's vasculature to an inflated state (as shown in FIG. 1 ) suitable for securing the catheter 102 in place relative to the treatment site 106. Stated differently, when the balloon 104 is in the inflated state, the balloon wall 130 of the balloon 104 is configured to be positioned substantially adjacent to the treatment site 106. While FIG. 1 illustrates the balloon wall 130 of the balloon 104 spaced apart from the treatment site 106 of the blood vessel 108 when in the inflated state, it will be understood that this is done solely for ease of illustration. It will be appreciated that the balloon wall 130 of the balloon 104 will typically be substantially directly adjacent to and / or abut the treatment site 106 when the balloon 104 is in the inflated state.

[0067] Balloons 104 suitable for use in the catheter system 100 include those that, when in a deflated state, are capable of passing through the vasculature of a patient 109. In some embodiments, the balloon 104 is made of silicone. In other embodiments, the balloon 104 can be made from polydimethylsiloxane (PDMS), polyurethane, a polymer such as PEBAX™ material, nylon, or any other suitable material.

[0068] Balloon 104 can have any suitable diameter (inflated state). In various embodiments, balloon 104 can have a diameter (inflated state) ranging from less than 1 millimeter (mm) to 25 mm. In some embodiments, balloon 104 can have a diameter (inflated state) ranging from at least 1.5 mm to 14 mm. In some embodiments, balloon 104 can have a diameter (inflated state) ranging from at least 2 mm to 5 mm.

[0069] In some embodiments, the balloon 104 can have a length ranging from at least 3 mm to 300 mm. More specifically, in some embodiments, the balloon 104 can have a length ranging from at least 8 mm to 200 mm. It is understood that a balloon 104 having a relatively long length can be positioned adjacent to a larger treatment site 106 and, therefore, can be used to apply pressure waves to induce fragmentation at a larger vascular lesion 106A or multiple vascular lesions 106A at precise locations within the treatment site 106. Furthermore, it is understood that a longer balloon 104 can also be positioned adjacent to multiple treatment sites 106 at any given time.

[0070] The balloon 104 may be inflated to an inflation pressure of approximately 1 atmosphere (atm) to 70 atm. In some embodiments, the balloon 104 may be inflated to an inflation pressure of at least 20 atm to 60 atm. In other embodiments, the balloon 104 may be inflated to an inflation pressure of at least 6 atm to 20 atm. In still other embodiments, the balloon 104 may be inflated to an inflation pressure of at least 3 atm to 20 atm. In still other embodiments, the balloon 104 may be inflated to an inflation pressure of at least 2 atm to 10 atm.

[0071] The balloon 104 can have a variety of shapes, including, but not limited to, a conical, square, rectangular, spherical, conical / square, conical / spherical, elongated spherical, elliptical, tapered, bone, stepped diameter, offset, or conical offset. In some embodiments, the balloon 104 can include a drug-eluting coating or a drug-eluting stent structure. The drug-eluting coating or drug-eluting stent can include one or more therapeutic agents, including anti-inflammatory agents, anti-neoplastic agents, anti-angiogenic agents, etc.

[0072] The balloon fluid 132 can be a liquid or a gas. Some examples of balloon fluids 132 suitable for use can include, but are not limited to, one or more of water, saline, a contrast medium, a gas such as a fluorocarbon, a perfluorocarbon, carbon dioxide, or any other suitable balloon fluid 132. In some embodiments, the balloon fluid 132 can be used as a base inflation fluid. In some embodiments, the balloon fluid 132 can include a mixture of saline and a contrast medium in a volume ratio of approximately 50:50. In other embodiments, the balloon fluid 132 can include a mixture of saline and a contrast medium in a volume ratio of approximately 25:75. In yet other embodiments, the balloon fluid 132 can include a mixture of saline and a contrast medium in a volume ratio of approximately 75:25. However, it will be understood that any suitable ratio of saline to contrast medium can be used. The balloon fluid 132 can be tailored based on its composition, viscosity, etc., to appropriately manipulate the speed at which the pressure waves travel. In certain embodiments, balloon fluids 132 suitable for use herein are biocompatible. The volume of the balloon fluid 132 can be adjusted depending on the light source 124 selected and the type of balloon fluid 132 used.

[0073] In some embodiments, the contrast agent used in the contrast medium can include, but is not limited to, an iodine-based contrast agent, such as an ionic or non-ionic iodine-based contrast agent. Some non-limiting examples of ionic iodine-based contrast agents include diatrizoate, metrizoate, iothalamate, and ioxaglate. Some non-limiting examples of non-ionic iodine-based contrast agents include iopamidol, iohexol, ioxilan, iopromide, iodixanol, and ioversol. In other embodiments, non-iodine-based contrast agents can be used. Suitable non-iodine-containing contrast agents can include gadolinium(III)-based contrast agents. Suitable fluorocarbon and perfluorocarbon agents can include, but are not limited to, agents such as the perfluorocarbon dodecafluoropentane (DDFP, C5F12).

[0074] The balloon fluid 132 can include an absorber that can selectively absorb light in the ultraviolet (e.g., at least 10 nanometers (nm) to 400 nm), visible (e.g., at least 400 nm to 780 nm), or near-infrared (e.g., at least 780 nm to 2.5 μm) regions of the electromagnetic spectrum. Suitable absorbers can include those that have an absorption maximum along a spectrum of at least 10 nm to 2.5 μm. Alternatively, the balloon fluid 132 can include an absorber that can selectively absorb light in the mid-infrared (e.g., at least 2.5 μm to 15 μm) or far-infrared (e.g., at least 15 μm to 1 μm) regions of the electromagnetic spectrum. In various embodiments, the absorber can have an absorption maximum that coincides with the emission maximum of a laser used in the catheter system 100. By way of non-limiting example, various lasers described herein may include a neodymium:yttrium-aluminum-garnet (Nd:YAG—emission maximum=1064 nm) laser, a holmium:YAG (Ho:YAG—emission maximum=2.1 μm) laser, or an erbium:YAG (Er:YAG—emission maximum=2.94 μm) laser. In some embodiments, the absorber may be water-soluble. In other embodiments, the absorber is not water-soluble. In some embodiments, the absorber used in the balloon fluid 132 may be tailored to match the peak emission of the light source 124. Various light sources 124 having emission wavelengths of at least 10 nanometers to 1 millimeter are discussed elsewhere herein.

[0075] The catheter shaft 110 of the catheter 102 can be coupled to one or more light guides 122A of the light guide bundle 122 in optical communication with the light sources 124. The light guide(s) 122A can be disposed along the catheter shaft 110 and within the balloon 104. Each of the light guides 122A can have a distal guide end 122D at any suitable longitudinal position relative to the length of the balloon 104. In some embodiments, each light guide 122A can be an optical fiber, and the light source 124 can be a laser. The light source 124 can be in optical communication with the light guides 122A at the proximal portion 114 of the catheter system 100. More specifically, the light source 124 can be in optical communication selectively, simultaneously, sequentially, and / or alternatively with each of the light guides 122A in any desired combination, order, and / or pattern.

[0076] In some embodiments, the catheter shaft 110 may be coupled to multiple light guides 122A, such as a first light guide, a second light guide, a third light guide, etc., which may be positioned at any suitable location around the guidewire lumen 118 and / or catheter shaft 110. For example, in certain non-exclusive embodiments, two light guides 122A may be spaced approximately 180 degrees apart around the circumference of the guidewire lumen 118 and / or catheter shaft 110, three light guides 122A may be spaced approximately 120 degrees apart around the circumference of the guidewire lumen 118 and / or catheter shaft 110, or four light guides 122A may be spaced approximately 90 degrees apart around the circumference of the guidewire lumen 118 and / or catheter shaft 110. Further alternatively, the multiple light guides 122A need not be uniformly spaced from one another around the circumference of the guidewire lumen 118 and / or catheter shaft 110. More specifically, the light guides 122A can be uniformly or non-uniformly positioned around the guidewire lumen 118 and / or catheter shaft 110 to achieve a desired effect at a desired location.

[0077] The catheter system 100 and / or light guide bundle 122 may include any number of light guides 122A in optical communication with the light source 124 at the proximal portion 114 and the balloon fluid 132 in the balloon interior 146 of the balloon 104 at the distal portion 116. For example, in some embodiments, the catheter system 100 and / or light guide bundle 122 may include from one light guide 122A to five light guides 122A. In other embodiments, the catheter system 100 and / or light guide bundle 122 may include from five light guides 122A to fifteen light guides 122A. In yet other embodiments, the catheter system 100 and / or light guide bundle 122 may include between ten light guides 122A and thirty light guides 122A. Alternatively, in still other embodiments, the catheter system 100 and / or light guide bundle 122 may include more than thirty light guides 122A.

[0078] The light guide 122A can have any suitable design for the purpose of generating plasma and / or pressure waves in the balloon fluid 132 within the balloon interior 146. In certain embodiments, the light guide 122A can include an optical fiber or a flexible light pipe. The light guide 122A can be thin and flexible, allowing for the transmission of optical signals with little loss of intensity. The light guide 122A can include a core surrounded by a cladding. In some embodiments, the core can be a cylindrical core or a partially cylindrical core. The core and cladding of the light guide 122A can be formed from one or more materials, including, but not limited to, one or more types of glass, silica, or one or more polymers. The light guide 122A can also include a protective coating, such as a polymer. It is understood that the refractive index of the core is greater than the refractive index of the cladding.

[0079] Each light guide 122A can direct first light energy along its length from a guide proximal end 122P having at least one optical window (not shown) positioned within the balloon interior 146 toward a guide distal end 122D.

[0080] In various embodiments, guide distal end 122D can further include and / or incorporate distal light receiver 122R that allows second light energy to be transmitted into and back through light guide 122A from guide distal end 122D to guide proximal end 122P. Stated another way, first light energy can generally travel in a first direction 121F along light guide 122A from guide proximal end 122P toward guide distal end 122D of light guide 122A. In certain circumstances, second light energy, which can include at least a portion of the first light energy, can travel in a second direction 121S along light guide 122A substantially opposite first direction 121F, i.e., from guide distal end 122D toward guide proximal end 122P of light guide 122A. Furthermore, as described in more detail herein below, the second light energy emitted from the guide proximal end 122P after being returned through the light guide 122A (in the second direction 121S) can be separated and then optically detected, matched, and / or analyzed using the optical analyzer assembly 142 to determine the exact operating mode associated with both non-fault and fault conditions of the light guide 122A.

[0081] The light guide 122A can take on many configurations around and / or relative to the catheter shaft 110 of the catheter 102. In some embodiments, the light guide 122A can extend parallel to the longitudinal axis 144 of the catheter shaft 110. In some embodiments, the light guide 122A can be physically coupled to the catheter shaft 110. In other embodiments, the light guide 122A can be disposed along the length of the outer diameter of the catheter shaft 110. In still other embodiments, the light guide 122A can be disposed within one or more light guide lumens within the catheter shaft 110.

[0082] The optical guides 122A may also be positioned at any suitable location around the guidewire lumen 118 and / or catheter shaft 110, and the guide distal ends 122D of each of the optical guides 122A may be positioned at any suitable longitudinal position relative to the length of the balloon 104 and / or relative to the length of the guidewire lumen 118 to more effectively and precisely apply pressure waves for the purpose of destroying the vascular lesions 106A at the treatment site 106.

[0083] In certain embodiments, the light guide 122A can include one or more optoacoustic transducers 154, and each optoacoustic transducer 154 can be in optical communication with the light guide 122A disposed therein. In some embodiments, the optoacoustic transducers 154 can be in optical communication with the distal guide end 122D of the light guide 122A. The optoacoustic transducers 154 can have a shape that corresponds to and / or matches the distal guide end 122D of the light guide 122A.

[0084] The photoacoustic transducer 154 is configured to convert the first light energy into acoustic waves at or near the distal guide end 122D of the light guide 122A, and the direction of the acoustic waves can be adjusted by changing the angle of the distal guide end 122D of the light guide 122A.

[0085] In certain embodiments, the optoacoustic transducer 154 disposed at the distal guide end 122D of the light guide 122A can have the same shape as the distal guide end 122D of the light guide 122A. For example, in certain non-exclusive embodiments, the optoacoustic transducer 154 and / or the distal guide end 122D can have a conical shape, a convex shape, a concave shape, a bulbous shape, a square shape, a stepped shape, a semicircular shape, an oval shape, etc. The light guide 122A can further include additional optoacoustic transducers 154 disposed along one or more sides of the length of the light guide 122A.

[0086] In some embodiments, the light guide 122A can further include one or more redirecting mechanisms or “diverters” (not shown in FIG. 1 ) within the light guide 122A configured to direct light to exit the light guide 122A toward a side surface, which may be located at or near the distal guide end 122D of the light guide 122A, and toward the balloon wall 130. The redirecting mechanisms can include any mechanism in the system that redirects the first light energy from the light guide 122A away from its axial path toward a side surface of the light guide 122A. The light guides 122A can each include one or more optical windows disposed along a longitudinal or circumferential surface of each light guide 122A and in optical communication with the redirecting mechanisms. Stated another way, the redirecting mechanisms can be configured to direct the first light energy within the light guide 122A toward a side surface, which may be located at or near the distal guide end 122D, the side surface being in optical communication with the optical windows. The optical window may include a portion of the light guide 122A that allows first light energy to exit the light guide 122A from within the light guide 122A, for example, a portion of the light guide 122A that does not have cladding material on or around the light guide 122A.

[0087] Examples of redirecting mechanisms suitable for use include reflective elements, refractive elements, and fiber diffusers. Redirecting mechanisms suitable for focusing the first optical energy away from the tip of the light guide 122A can include, but are not limited to, those with a convex surface, a gradient index (GRIN) lens, and a mirror focus lens. Upon contact with the redirecting mechanism, the first optical energy is redirected within the light guide 122A to one or more of the plasma generator 133 and an optoacoustic transducer 154, which is in optical communication with the sides of the light guide 122A. As described above, the optoacoustic transducer 154 converts the first optical energy into acoustic waves that extend away from the sides of the light guide 122A.

[0088] The source manifold 136 may be positioned at or near the proximal portion 114 of the catheter system 100. The source manifold 136 may include one or more proximal end openings that may receive one or more light guides 122A of the light guide bundle 122, the guidewire 112, and / or an inflation conduit 140 that is coupled in fluid communication with a fluid pump 138. The catheter system 100 may also include a fluid pump 138 configured to inflate the balloon 104 with balloon fluid 132 as needed.

[0089] As noted above, in the embodiment shown in Figure 1, the system console 123 includes one or more of the light source 124, the power supply 125, the system controller 126, and the GUI 127. Alternatively, the system console 123 may include more or fewer components than those specifically shown in Figure 1. For example, in certain non-exclusive alternative embodiments, the system console 123 may be designed without the GUI 127. Further alternatively, one or more of the light source 124, the power supply 125, the system controller 126, and the GUI 127 may be provided within the catheter system 100 without the specific need for a system console 123.

[0090] 1, in certain embodiments, at least a portion of the optical analyzer assembly 142 may be located substantially within the system console 123. Alternatively, the components of the optical analyzer assembly 142 may be positioned in a manner different from that specifically shown in FIG.

[0091] As shown, the system console 123 and its included components are operably coupled to the catheter 102, the light guide bundle 122, and the remainder of the catheter system 100. For example, in some embodiments, as shown in FIG. 1 , the system console 123 may include a console connection opening 148 (sometimes commonly referred to as a “socket”) through which the light guide bundle 122 is mechanically coupled to the system console 123. In such embodiments, the light guide bundle 122 may include a guide coupling housing 150 (sometimes commonly referred to as a “ferrule”) that accommodates a portion of each light guide 122A, such as the guide proximal end 122P. The guide coupling housing 150 is configured to fit within and selectively retain within the console connection opening 148 to provide a mechanical coupling between the light guide bundle 122 and the system console 123.

[0092] The light guide bundle 122 may also include a guide bundler 152 (or "shell") that brings each of the individual light guides 122A closer together, thereby allowing the light guides 122A and / or the light guide bundle 122 to assume a more compact form when extended into the blood vessel 108 along with the catheter 102 during use of the catheter system 100.

[0093] The light source 124 can be selectively and / or alternatively coupled in optical communication with each of the light guides 122A, such as the guide proximal end 122P of each of the light guides 122A in the light guide bundle 122. In particular, the light source 124 is configured to generate a first light energy in the form of a light source beam 124A, such as a pulsed light source beam, which can be selectively and / or alternatively directed to and received by each of the light guides 122A in the light guide bundle 122 as individual guide beams 124B. Alternatively, the catheter system 100 can include multiple light sources 124. For example, in one non-exclusive alternative embodiment, the catheter system 100 can include a separate light source 124 for each of the light guides 122A in the light guide bundle 122.

[0094] The light source 124 can have any suitable design. In certain embodiments, the light source 124 can be configured to provide a sub-millisecond pulse of first light energy from the light source 124 that is focused onto a small spot for coupling to the proximal guide end 122P of the light guide 122A. This pulse of first light energy is then directed and / or guided along the light guide 122A to a location within the balloon interior 146 of the balloon 104, thereby inducing plasma formation (also referred to herein as a "plasma flash") in the balloon fluid 132 within the balloon interior 146 of the balloon 104, such as via a plasma generator 133 that can be located at or near the distal guide end 122D of the light guide 122A. In particular, light emitted at the distal guide end 122D of the light guide 122A is directed at and excites the plasma generator 133 to form plasma within the balloon fluid 132 within the balloon interior 146. The plasma formation causes rapid bubble formation and imparts a pressure wave to the treatment site 106. An exemplary plasma-induced bubble 134 is shown in FIG.

[0095] When plasma initially forms in the balloon fluid 132 within the balloon interior 146, it emits broad-spectrum electromagnetic radiation. This is visible as a broad-spectrum flash of light detectable to the naked eye. A portion of the light emitted from the plasma bubble 134, in the form of a second light energy, can be coupled to the distal light receiver 122R at the distal guide end 122D of the light guide 122A and travel back to the proximal guide end 122P, where it can be separated, detected, and analyzed through the use of the optical analyzer assembly 142. The intensity and timing of the visible light pulse relative to the plasma-generating pulse provides an indication that the plasma generator 133 has functioned, its energy output, and its functional or operational state. If the light guide 122A is damaged or broken, visible light flashes can occur at other locations on the light guide 122A. Such other visible light flashes can also be coupled into the light guide 122A and transported back to the proximal guide end 122P. The intensity and timing of these other light pulses may provide an indication of damage or failure of the light guide 122A or the plasma generator 133. In such circumstances, the optical analyzer assembly 142 may include a safety shutdown system 283 (shown in FIG. 2A) that may be selectively activated to shut down operation of the catheter system 100.

[0096] 3A-3F , the optical analyzer assembly 142 can be configured to detect specific functional or operational conditions of the light guide 122A and / or the plasma generator 133, such as (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a distal guide end plasma initiation condition, (iv) a housing / target fault condition, (v) a light guide break (fiber) condition, such as due to a light guide break at the distal guide end, and (vi) a chewback condition, such as due to a light guide break along the light guide and at least some distance from the distal guide end. It is understood that some of the identified operational conditions, including the normal operating condition, the intermittent bubble generation condition, and the distal guide end plasma initiation condition, may require further monitoring of the condition of the light guide 122A and / or the plasma generator 133, but do not require immediate cessation of operation of the catheter system 100 or replacement of the light guide 122A and / or the plasma generator 133. However, it is further understood that other identified operating conditions, such as a housing / target failure condition, a light guide broken (fiber) condition, and a chewback condition, may, and often do, require the catheter system 100 to cease operation and replacement of the light guide 122A and / or plasma generator 133.

[0097] The configuration of the plasma generator 133 and / or distal optical receiver 122R further allows ambient light emanating from outside the catheter 102 to be coupled into the distal guide end 122D of the light guide 122A. In one embodiment, the optical analyzer assembly 142 monitors return ambient light energy traversing the light guide 122A from the distal guide end 122D to the proximal guide end 122P. If ambient light energy is present and detected by the optical analyzer assembly 142 in such a situation, this is an indication that the catheter 102 is located outside the body 107 of the patient 109, and the optical analyzer assembly 142 can be configured to lock out the light source 124 accordingly. Notably, in such a situation, the safety shutdown system 283 of the optical analyzer assembly 142 can be selectively activated to shut down operation of the catheter system 100.

[0098] In various non-exclusive alternative embodiments, the submillisecond pulses of first light energy from the light source 124 may be delivered to the treatment site 106 at a frequency between about 1 Hertz (Hz) and 5000 Hz, between about 30 Hz and 1000 Hz, between about 10 Hz and 100 Hz, or between about 1 Hz and 30 Hz. Alternatively, the submillisecond pulses of first light energy may be delivered to the treatment site 106 at a frequency that may be greater than 5000 Hz or less than 1 Hz, or any other suitable frequency range.

[0099] Although light source 124 is typically utilized to provide a first pulse of light energy, it is understood that light source 124 may be described as providing a single light source beam 124A, i.e., a single pulsed light source beam.

[0100] Suitable light sources 124 for use can include various types of light sources, including lasers and lamps. For example, in certain non-exclusive embodiments, the light source 124 can be an infrared laser that emits the first light energy in the form of pulses of infrared light. Alternatively, as noted above, the light sources 124 referred to herein can include any suitable type of energy source.

[0101] Suitable lasers include short-pulse lasers on the submillisecond timescale. In some embodiments, the light source 124 can include a laser on the nanosecond (ns) timescale. Lasers can also include short-pulse lasers on the picosecond (ps), femtosecond (fs), and microsecond (us) timescales. It is understood that there are many combinations of laser wavelengths, pulse widths, and energy levels that can be employed to achieve a plasma in the balloon fluid 132 of the catheter 102. In various non-exclusive alternative embodiments, pulse widths can include those in ranges including at least 10 ns to 3000 ns, at least 20 ns to 100 ns, or at least 1 ns to 500 ns. Alternatively, any other suitable pulse width range can be used.

[0102] Exemplary nanosecond lasers can include those in the UV to IR spectrum, spanning wavelengths from approximately 10 nanometers (nm) to 1 millimeter (mm). In some embodiments, the light source 124 suitable for use in the catheter system 100 can include those capable of generating light with wavelengths of at least 750 nm to 2000 nm. In other embodiments, the light source 124 can include those capable of generating light with wavelengths of at least 700 nm to 3000 nm. In still other embodiments, the light source 124 can include those capable of generating light with wavelengths of at least 100 nm to 10 micrometers (μm). Nanosecond lasers can include those having repetition rates up to 200 kHz. In some embodiments, the laser can include a Q-switched thulium:yttrium-aluminum-garnet (Tm:YAG) laser. In other embodiments, the laser may include a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser, a holmium:yttrium-aluminum-garnet (Ho:YAG) laser, an erbium:yttrium-aluminum-garnet (Er:YAG) laser, an excimer laser, a helium-neon laser, a carbon dioxide laser, and a doped pulsed fiber laser.

[0103] The catheter system 100 can generate pressure waves having a maximum pressure in the range of at least 1 megapascal (MPa) to 100 MPa. The maximum pressure generated by a particular catheter system 100 depends on the light source 124, the absorbing material, the bubble expansion, the propagation medium, the balloon material, and other factors. In various non-exclusive alternative embodiments, the catheter system 100 can generate pressure waves having a maximum pressure in the range of at least about 2 MPa to 50 MPa, at least about 2 MPa to 30 MPa, or at least about 15 MPa to 25 MPa.

[0104] The pressure waves may be applied to the treatment site 106 from a distance ranging from at least about 0.1 millimeters (mm) to greater than about 25 mm extending radially from the light guide 122A when the catheter 102 is positioned at the treatment site 106. In various non-exclusive alternative embodiments, the pressure waves may be applied to the treatment site 106 from a distance ranging from at least about 10 mm to 20 mm, at least about 1 mm to 10 mm, at least about 1.5 mm to 4 mm, or at least about 0.1 mm to 10 mm extending radially from the light guide 122A when the catheter 102 is positioned at the treatment site 106. In other embodiments, the pressure waves may be applied to the treatment site 106 from another suitable distance different from the aforementioned ranges. In some embodiments, the pressure waves may be applied to the treatment site 106 from a distance of at least about 0.1 mm to 10 mm and within a range of at least about 2 MPa to 30 MPa. In some embodiments, pressure waves may be applied onto the treatment site 106 in the range of at least about 2 MPa to 25 MPa over a distance of at least about 0.1 mm to 10 mm. Further alternatively, other suitable pressure ranges and distances may be used.

[0105] The power supply 125 is electrically coupled to and configured to provide the necessary power to each of the light source 124, the system controller 126, the GUI 127, the handle assembly 128, and the optical analyzer assembly 142. The power supply 125 may have any suitable design for such purpose.

[0106] The system controller 126 is electrically coupled to the power source 125 and receives power from the power source. The system controller 126 is coupled to each of the light source 124, the GUI 127, and the optical analyzer assembly 142 and configured to control their operation. The system controller 126 may include one or more processors or circuits for the purpose of controlling the operation of at least the light source 124, the GUI 127, and the optical analyzer assembly 142. For example, the system controller 126 may control the light source 124 to generate pulses of first light energy as desired and / or at any desired firing rate. The system controller 126 may control and / or operate in conjunction with the optical analyzer assembly 142 to effectively provide real-time, continuous monitoring of the performance, reliability, safety, and proper use of the catheter system 100.

[0107] The system controller 126 may be further configured to control the operation of other components of the catheter system 100, such as positioning the catheter 102 adjacent the treatment site 106, inflation of the balloon 104 with balloon fluid 132, etc. Additionally or alternatively, the catheter system 100 may include one or more additional controllers, which may be positioned in any suitable manner for the purpose of controlling various operations of the catheter system 100. For example, in certain embodiments, the additional controllers and / or portions of the system controller 126 may be positioned within and / or incorporated within the handle assembly 128.

[0108] The GUI 127 is accessible by a user or operator of the catheter system 100. The GUI 127 is electrically connected to the system controller 126. With such a design, the GUI 127 can be used by the user or operator to ensure that the catheter system 100 is effectively utilized to apply pressure on the treatment site(s) 106 to induce fragmentation. The GUI 127 can provide the user or operator with information that can be used before, during, and after use of the catheter system 100. In one embodiment, the GUI 127 can provide the user or operator with static visual data and / or information. Additionally or alternatively, the GUI 127 can provide the user or operator with dynamic visual data and / or information, such as video data or any other data that changes over time during use of the catheter system 100. In various embodiments, the GUI 127 can include one or more colors, different sizes, varying brightness, etc., that can serve as alerts to the user or operator. Additionally or alternatively, the GUI 127 can provide the user or operator with audio data or information. The details of the GUI 127 may vary depending on the design requirements of the catheter system 100 or the particular needs, specifications and / or desires of a user or operator.

[0109] 1, the handle assembly 128 can be positioned at or near the proximal portion 114 of the catheter system 100 and / or near the source manifold 136. In this embodiment, the handle assembly 128 is coupled to and positioned spaced apart from the balloon 104. Alternatively, the handle assembly 128 can be positioned in another suitable location.

[0110] The handle assembly 128 is handled and used by a user or operator to operate, position, and control the catheter 102. The design and specific features of the handle assembly 128 can be varied to suit the design requirements of the catheter system 100. In the embodiment shown in FIG. 1 , the handle assembly 128 is separate from, but in electrical and / or fluid communication with, one or more of the system controller 126, the light source 124, the fluid pump 138, the GUI 127, and the optical analyzer assembly 142. In some embodiments, the handle assembly 128 can integrate and / or include at least a portion of the system controller 126 within the handle assembly 128. For example, as shown, in certain such embodiments, the handle assembly 128 can include circuitry 156 that can form at least a portion of the system controller 126. In some embodiments, the circuitry 156 can receive electrical signals or data from the optical analyzer assembly 142. Additionally or alternatively, the circuitry 156 can transmit such electrical signals or otherwise provide data to the system controller 126.

[0111] In one embodiment, circuitry 156 may include one or more integrated circuits or a printed circuit board having any other suitable circuitry. In alternative embodiments, circuitry 156 may be omitted or may be included within system controller 126, and in various embodiments, circuitry 156 may be located outside of handle assembly 128, such as in system console 123. It is understood that handle assembly 128 may include fewer or additional components than those specifically shown and described herein.

[0112] In summary, as provided in more detail herein, the optical analyzer assembly 142 is configured to effectively monitor the performance, reliability, safety, and proper use of the catheter system 100. During use of the catheter system 100, when plasma initially forms in the balloon fluid 132 within the balloon interior 146, a first pulse of light energy is directed into the balloon fluid 132 within the balloon interior 146, resulting in a plasma flash emitting broad-spectrum electromagnetic radiation. The plasma flash can be effectively captured in the form of a flash signature (or flash signal) which can include summary parameters such as pulse maximum, rise time, width, and onset time relative to a baseline, as well as a measure of signal variability (described as a transition count), all of which can provide an indication of the condition of the light guide 122A and / or the plasma generator 133.

[0113] At least a portion of the emitted first light energy can be reflected from or otherwise received by distal light receiver 122R near distal guide end 122D of light guide 122A. Accordingly, such portion of the first light energy can return through light guide 122A to proximal guide end 122P as second light energy traveling in second direction 121S, where it can be separated, detected, and analyzed through the use of optical analyzer assembly 142. The intensity and timing of the visible light pulse relative to the plasma-generating pulse from light source 124 provides an indication that plasma generator 133 has functioned, its energy output, and its functional status. It is understood that if light guide 122A is damaged or broken, visible light flashes can occur at other locations along the length of light guide 122A. Such additional light flashes are also coupled into light guide 122A and conveyed back to proximal guide end 122P in second direction 121S. The intensity and timing of these additional light pulses can indicate a damaged light guide 122A or plasma generator 133.

[0114] By evaluating and / or analyzing the intensity and timing of the visible light pulse relative to the plasma generating pulse from the light source 124, the optical analyzer assembly 142 can determine: (i) a normal operating condition in which a first optical energy is directed from the guide distal end 122D of the light guide 122A toward the plasma generator 133, and thus a plasma is generated substantially immediately adjacent to the plasma generator 133 when it strikes the target surface of the plasma generator 133; (ii) a condition in which a gas bubble formed within the balloon fluid 132 is directed toward the guide distal end 122D of the light guide 122A; (iii) a guide distal end plasma initiation condition, in which some debris may be present substantially adjacent to guide distal end 122D of light guide 122A, causing plasma to be generated at such point substantially adjacent to guide distal end 122D of light guide 122A, but not substantially directly adjacent to plasma generator 133; (iv) a guide distal end plasma initiation condition, in which some debris may be present substantially adjacent to guide distal end 122D of light guide 122A, causing plasma to be generated at such point substantially adjacent to guide distal end 122D of light guide 122A, but not substantially directly adjacent to plasma generator 133; (v) a light guide break (fiber) condition, such as a broken light guide 122A at the guide distal end 122D, where little or no plasma is generated in the balloon fluid 132 within the balloon interior 146 and any minimum plasma that may be generated has a lower pulse maximum value because the first light energy is directed in multiple different directions away from the guide distal end 122D of the light guide 122A rather than simply directly toward the plasma generator 133; or (vi) a chewback condition, such as a broken light guide 122A along the length of the light guide 122A and at least some distance from the guide distal end 122D, where plasma generation may occur in the balloon fluid 132 within the balloon interior 146 substantially adjacent to where the break may exist along the length of the light guide 122A.It is understood that some of these identified operating conditions, including a normal operating condition, an intermittent bubble generation condition, and a guide distal end plasma initiation condition, may require further monitoring of the condition of the light guide 122A and / or the plasma generator 133, but do not require immediate cessation of operation of the catheter system 100 or replacement of the light guide 122A and / or the plasma generator 133. However, it is further understood that other identified operating conditions, such as a housing / target failure condition, a light guide broken (fiber) condition, and a chewback condition, may, and often do, require cessation of operation of the catheter system 100 and replacement of the light guide 122A and / or the plasma generator 133.

[0115] It is understood that misuse or failure of the energy-driven plasma generator 133 or associated light guide 122A, such as when the light guide 122A and / or catheter system 100 are used outside the body 107 of the patient 109 and / or when the light guide 122A is broken or damaged during use of the catheter system 100, could result in harm to the patient or operator due to leaked energy. Potential hazards include tissue burns and retinal damage. As noted above, in some embodiments, the light source 124 is a laser that emits invisible infrared light, precluding visual detection by the operator. Therefore, if the optical analyzer assembly 142 indicates that such misuse or failure has occurred, treatment and energy delivery, such as laser energy delivery, must be immediately stopped to mitigate the associated risks to the patient and operator. Stated differently, with the design of the optical analyzer assembly 142 described herein, the present invention provides an indicator or signal that can be used by the system controller 126 to detect misuse of the catheter system 100 and / or any of the above-mentioned misuse or failures within the catheter system 100, such as breakage, damage, or failure of the light guide 122A and / or plasma generator 133, and to lock out the light source 124. In certain embodiments, locking out the light source 124 can be achieved through the use of a safety shutdown system 283, which in some such embodiments can include one or more of a safety interlock 284 (shown in FIG. 2A ) and a shutter 286 (shown in FIG. 2A ), which can be incorporated as part of the optical analyzer assembly 142. This provides the necessary safety interlock and mitigation against a potentially dangerous situation in which the light source 124 could leak from any portion of the catheter system 100 or light guide 122A due to misuse or failure. Additionally, the system controller 126 can be used to instruct the surgeon, such as via the GUI 127, to stop the procedure and remove the catheter 102 from the patient 109 being treated.A simple example of potential misuse is attempting to excite the catheter system 100 when it is outside the body 107 of the patient 109 and / or away from the intended treatment site 106. The emitted energy could be unintentionally seen by the operator and result in retinal damage.

[0116] It is further understood that the optical analyzer assembly 142 can have any suitable design for the purpose of effectively monitoring the safety, performance, reliability, and proper use of the catheter system 100. Specific, non-exclusive examples of potential designs and applications of the optical analyzer assembly 142 are described in detail herein below.

[0117] Figure 2A is a simplified schematic diagram of a portion of an embodiment of a catheter system 200 including an embodiment of an optical analyzer assembly 242. As shown in Figure 2A, the optical analyzer assembly 242 is utilized in a first application. Figure 2B is a simplified schematic diagram of a portion of the catheter system 200 including the optical analyzer assembly 242 of Figure 2A. As shown in Figure 2B, the optical analyzer assembly 242 is utilized in a second application.

[0118] The design of the catheter system 200 is substantially similar to the embodiments described herein above. It is understood that various components of the catheter system 200, such as those shown in Figure 1, are not shown in Figures 2A and 2B for clarity and ease of illustration. However, it is understood that the catheter system 200 is likely to include most, if not all, such components.

[0119] As shown in Figures 2A and 2B, catheter system 200 again includes a light source 224 configured to generate a first light energy in the form of a light source beam 224A, such as a pulsed light source beam, which can be selectively and / or alternatively directed to and received by each light guide 222A (only one light guide is shown in Figures 2A and 2B) as individual guide beams 224B (shown in Figure 2A). In one non-exclusive embodiment, light source 224 is an infrared laser source, and light guide 222A is a small-diameter multimode optical fiber. In the embodiment shown in Figures 2A and 2B, a pulse generator 260 is coupled to light source 224. Pulse generator 260 is configured to trigger light source 224, thereby emitting an energy pulse as light source beam 224A.

[0120] 2A , light source beam 224A from light source 224 passes through first optical element 262, such as a combining and / or focusing lens, configured to focus light source beam 224A as individual guide beams 224B onto proximal guide end 222P of light guide 222A, thereby coupling individual guide beams 224B into light guide 222A in the form of pulses of infrared energy (first light energy). Individual guide beams 224B then travel along and / or through light guide 222A as first light energy and excite plasma generator 233 positioned at and / or incorporated near distal guide end 222D of light guide 222A. Plasma generator 233 utilizes the pulses of infrared energy to generate localized plasma 234 (e.g., in the form of plasma bubbles or plasma flashes) in balloon fluid 132 (shown in FIG. 1 ) within balloon interior 146 (shown in FIG. 1 ) of balloon 104 (shown in FIG. 1 ).

[0121] 2A , upon generating plasma 234 in balloon fluid 132 within balloon interior 146, in various embodiments, pulses of broad-spectrum light energy emitted from plasma flash 234 in the form of second light energy are coupled back to distal guide end 222D of light guide 222A via distal light receiver 222R. Such pulses of broad-spectrum light energy (second light energy) then travel back along and / or through light guide 222A, from where they are emitted from proximal guide end 222P of light guide 222A as second light energy 224C.

[0122] 2B, in some applications, ambient light 235 near distal guide end 222D of light guide 222A can be coupled into distal guide end 222D of light guide 222A via distal light receiver 222R. Such ambient light energy (second light energy) then travels along and through light guide 222A toward proximal guide end 222P of light guide 222A, from which it is emitted as second light energy 224C (sometimes also referred to in this application as an “ambient energy beam”).

[0123] As described in detail herein, the optical analyzer assembly 242 is configured to effectively monitor the performance, reliability, safety, and proper use of the catheter system 200 by optically analyzing the second light energy emitted from the proximal guide end 222P of the light guide 222A. In other words, the optical analyzer assembly 242 is configured to effectively monitor the performance, reliability, safety, and proper use of the catheter system 200 by optically analyzing (i) the second light energy 224C generated as a result of the plasma flash 234 created by the plasma generator 233 in the balloon fluid 132 within the balloon interior 146 of the balloon 104, and / or (ii) the second light energy 224C in the form of an ambient energy beam 235 coupled into the distal guide end 222D of the light guide 222A via the distal light receiver 222R.

[0124] 2A and 2B, the optical analyzer assembly 242 includes one or more of a first beam splitter 264, a first optical element 262, a second optical element 266, such as an imaging lens in one non-exclusive embodiment, a second beam splitter 268, a first filter 270, a photodetector 272, an amplifier 274, control electronics 276, which may include one or more processors or circuits, a second filter 278, an imaging device 280, such as a camera or other suitable imaging device, a device controller 282, and a safety shutdown system 283. As shown, the safety shutdown system 283 may include one or more of a safety interlock 284 and a shutter 286. Alternatively, in other embodiments, the optical analyzer assembly 242 and / or the safety shutdown system 283 may include more or fewer components than those specifically shown and described herein. Further alternatively, in still other embodiments, the various components of the optical analyzer assembly 242 may be positioned differently than those specifically shown in Figures 2A and 2B.

[0125] As shown in the first application shown in FIG. 2A , in one embodiment, a first beam splitter 264, such as a dichroic beam splitter, is positioned in the optical path of the light source beam 224A between the light source 224 and the guide proximal end 222P of the light guide 222A. In certain embodiments, the beam splitter 264 is configured to pass light with wavelengths longer than the wavelength visible to the photodetector 272 to provide individual guide beams 224B that are directed toward the guide proximal end 222P of the light guide 222A. Such a threshold wavelength can be referred to as a cutoff wavelength. The beam splitter 264 is further configured to reflect all light having wavelengths shorter than the cutoff wavelength. As shown in this embodiment, the first optical element 262 is positioned between the first beam splitter 264 and the light guide 222A and configured to focus the individual guide beams 224B onto the guide proximal end 222P of the light guide 222A, thereby coupling the individual guide beams 224B into the light guide 222A.

[0126] The first light energy of each guide beam 224B is guided along light guide 222A from proximal guide end 222P to distal guide end 222D, exciting a plasma generator 233 positioned at and / or incorporated into light guide 222A at or near distal guide end 222D. Plasma generator 233 utilizes pulses of infrared energy to create a localized plasma 234 in the balloon fluid 132 within balloon interior 146 of balloon 104. The pulses of broad-spectrum light energy emitted from plasma flash 234 as a form of second light energy are then recoupled into distal guide end 222D of light guide 222A and return along and / or through light guide 222A, from which they are emitted from proximal guide end 222P of light guide 222A as second light energy 224C.

[0127] 2A , second optical energy 224C emitted from guide proximal end 222P of light guide 222A is collimated by first optical element 262 and then directed back toward first beam splitter 264. At least a portion of second optical energy 224C is then redirected and / or reflected by first beam splitter 264 toward second beam splitter 268. Second optical element 266 is positioned in the optical path of the redirected portion of second optical energy 224C between first beam splitter 264 and second beam splitter 268. The optics of second optical element 266 focus the collimated second optical energy 224C toward second beam splitter 268. Second beam splitter 268 then redirects and / or reflects a portion of the collimated second optical energy 224C through a first filter 270, such as a bandpass filter in certain embodiments, onto photodetector 272, thus forming an image of proximal guide end 222P of light guide 222A on photodetector 272, thereby coupling second optical energy 224C emitted from proximal guide end 222P of light guide 222A onto photodetector 272. In certain embodiments, photodetector 272 may be a photodiode or another suitable type of photodetector. With this design, visible light emitted from plasma flash 234 formed at distal guide end 222D of light guide 222A is collected by photodetector 272.

[0128] In some embodiments, the photodetector 272 generates a signal based on visible light emitted from the plasma formed at the distal guide end 222D of the light guide 222A that is collected by the photodetector 272. As shown in FIG. 2A , the signal from the photodetector 272 is then directed to an amplifier 274 and control electronics 276, where a detection and intensity assessment of the plasma flash 234 is determined. Specifically, in certain embodiments, the signal from the photodetector 272 is directed to the amplifier 274, where the signal from the photodetector 272 is amplified. The amplified signal is then utilized within the control electronics 276 to determine the intensity of the plasma flash 234 generated within the balloon fluid 132 within the balloon interior 146.

[0129] In certain embodiments, the pulse from the amplified photodetector signal can be gated using a discriminator (not shown), such as a discriminator circuit triggered by a pulse from the pulse generator 260. This information can then be used in the control electronics 276 to determine when the plasma flash 234 occurred in the balloon fluid 132 within the balloon interior 146. More specifically, the control electronics 276 can compare the timing of the original energy pulse from the light source 224, triggered by the pulse generator 260, with the timing of the amplified photodetector signal, gated using the discriminator, to determine when the plasma flash 234 occurred in the balloon fluid 132 within the balloon interior 146.

[0130] In some embodiments, the control electronics 276 may be included as part of the system controller 126 (shown in FIG. 1 ). Alternatively, the control electronics 276 may be provided separately from the system controller 126 and may be in electrical communication with the system controller 126.

[0131] It is understood that there are numerous other configurations for the photodetector 272 required to detect and analyze the light pulses returning from the light guide 222A in the form of the second light energy 224C. For example, in another embodiment, the photodetector 272 can be a spectrometer that provides intensity and wavelength information about the second light energy 224C. In such an embodiment, this information can be used to generate a spectral (or flash) signature to further identify specific conditions or events within the light guide 222A and / or the plasma generator 233. More specifically, small amounts of material comprising the plasma generator 233 are vaporized during its normal operation. These produce distinct spectral lines. It is further understood that this technique can also be used to distinguish between a functioning plasma generator 233 and a broken or damaged light guide 222A. This can also be used to monitor external light entering the light guide 222A and / or the catheter system 200, such as an indoor light spectral signature.

[0132] Another application of the present invention would be to monitor the condition of the light guides 222A for the plasma generator 233. When the light guides 222A are first coupled to the catheter system 200, the light returned through the light guides 222A can be monitored to determine that all of the light guides 222A are intact.

[0133] 2A, a first application of the present invention involves the direct detection of a light pulse created by a plasma flash 234 in the balloon fluid 132 within the balloon interior 146. An optical analyzer assembly 242 can be utilized to indicate the intensity of the light pulse, its spectrum, and when the light pulse occurs relative to the input pulse from the light source 224. This can be interpreted as follows:

[0134] 1) The light pulse must occur after a time interval determined by the length of light guide 222A and the duration of the input energy pulse from light source 224. If the detected light pulse has the correct intensity and occurs within a specific time window, it is an indication that plasma generator 233 has functioned correctly.

[0135] 2) If no light pulse is detected at all, this is an indication of a failure of the plasma generator 233, the light source 224 and / or the entire catheter system 200.

[0136] 3) If a smaller light pulse is detected that occurs too soon relative to the energy pulse from light source 224, this is an indication of a failure and / or damage to light guide 222A.

[0137] 4) If the light pulses are detected to have a different spectrum or lack a spectral line or signature, this can be used to indicate a fault in the catheter system 200.

[0138] In the event of any detected failure of the plasma generator 233, the light source 224, the light guide 222A, and / or the entire catheter system 200, the control electronics 276 can be configured to send a signal to a safety shutdown system 283 to shut down operation of the catheter system 200. More specifically, in this embodiment, the signal from the control electronics 276 to the safety shutdown system 283 can be used to activate a safety interlock 284, which blocks signals from the pulse generator 260 to the light source 224, thus effectively stopping the generation of light pulses from the light source 224. Additionally or alternatively, the signal from the control electronics 276 to the safety shutdown system 283 can be used to activate a closeable shutter 286, thereby blocking any light pulses from the light source 224 that would otherwise be directed at and coupled to the light guide 222A. Such a safety shutdown system 283 can effectively limit potential injury to the patient 109 or operator.

[0139] 2B, a second application for the optical analyzer assembly 242 is shown and described. Specifically, in this second application, proper use of the catheter system 200 can be initially monitored prior to the generation of an energy pulse by the light source 224.

[0140] As shown, distal light receiver 222R can be configured to receive any ambient light 235 that may be present in the region of distal guide end 222D of light guide 222A. Specifically, any visible ambient light 235 that is present in the region of distal guide end 222D of light guide 222A can be coupled into distal guide end 222D of light guide 222A via distal light receiver 222R as second light energy 224C in the form of an ambient energy beam.

[0141] Second light energy 224C travels along and / or through light guide 222A from distal guide end 222D to proximal guide end 222P, from which it is emitted from proximal guide end 222P of light guide 222A. As shown in FIG. 2B , second light energy 224C emitted from proximal guide end 222P of light guide 222A is collimated by first optical element 262 and then directed toward first beam splitter 264. At least a portion of second light energy 224C is then redirected and / or reflected by first beam splitter 264 toward second beam splitter 268. Second optical element 266 is positioned in the optical path of the redirected portion of second light energy 224C between first beam splitter 264 and second beam splitter 268. The optics of second optical element 266 focus collimated second light energy 224C toward second beam splitter 268. Second beam splitter 268 then transmits at least a portion of collimated second light energy 224C through second filter 278, such as a short-pass filter in certain embodiments, to imaging device 280, thus forming an image of proximal guide end 222P of light guide 222A on imaging device 280, thereby coupling second light energy 224C emitted from proximal guide end 222P of light guide 222A onto imaging device 280. Thus, in a suitable arrangement, first optical element 262 and second optical element 266 can cooperate to create a high-resolution image of proximal guide end 222P of light guide 222A on imaging device 280. In certain embodiments, imaging device 280 can be an area sensor, such as a CCD or CMOS camera, or another suitable type of imaging device. With this design, visible ambient light 235 collected at distal guide end 222D of light guide 222A is collected by imager 280.

[0142] In some embodiments, imaging device 280, under the control of device controller 282, generates a signal based on visible ambient light 235 collected by imaging device 280 at distal guide end 222D of light guide 222A. As shown in FIG. 2B , the signal from imaging device 280 is then directed to control electronics 276, which determines the detection of any potential ambient light 235 near distal guide end 222D of light guide 222A. Specifically, in certain embodiments, the signal from imaging device 280 is utilized within control electronics 276 to determine whether ambient light 235 is present near distal guide end 222D of light guide 222A.

[0143] If the ambient light 235 is not detected by the optical analyzer assembly 242 as being collected from a region of the light guide 222A near the distal end 222D, this is an indication that the catheter system 200 is not being utilized in an improper manner. However, if the optical analyzer assembly 242 detects a change in the light returning from the light guide 222A, thereby signaling the ambient light 235 originating from outside the catheter system 200, this is an indication that the catheter system 200 is being used in an unintended manner. In such a situation, the control electronics 276 can be configured to send a signal to the safety shutdown system 283 to shut down operation of the catheter system 200. More specifically, in this embodiment, the signal from the control electronics 276 to the safety shutdown system 283 can be used to activate the safety interlock 284, which interrupts the signal from the pulse generator 260 to the light source 224, thus effectively stopping the generation of light pulses from the light source 224. Additionally or alternatively, a signal from the control electronics 276 to the safety shutdown system 283 can be used to activate a shutter 286 that can be closed, thereby blocking any light pulses from the light source 224 that would otherwise be directed at and coupled to the light guide 222A. Such a safety shutdown system 283 can effectively limit potential injury to the patient 109 or the operator.

[0144] 2A and 2B, the optical analyzer assembly 242 utilizes a second beam splitter 268 and separate filters 270, 278 to couple the second light energy 224C to both the imager 280 (an area sensor) and the photodetector 272 (a single-element photodetector, such as a photodiode). However, it is understood that the above-described uses of the catheter system 200 and / or the optical analyzer assembly 242 can be implemented in any suitable manner and may be performed somewhat differently than described in detail herein. For example, in one non-exclusive alternative embodiment, the photodetector 272 of the optical analyzer assembly 242 can be used to monitor the ambient light 235 coupled into the guide distal end 222D of the light guide 222A, as well as to monitor the light pulses created by the plasma flash 234 in the balloon fluid 132 within the balloon interior 146. In such an alternative embodiment, the imager 280 is not used or may be omitted from the catheter system.

[0145] In summary, application of the optical analyzer assembly 242 as shown in Figures 2A and 2B, which is configured to monitor the nominal operation of the catheter system 200 as well as potential misuse of the catheter system 200, can include the following general steps. (1) The catheter system starts from standby mode. (2) The catheter system continuously monitors use via an optical analyzer assembly and / or imaging device (sometimes referred to as an image sensor subsystem) looking for evidence of ambient light transmitted from the distal end of the light guide (as evidence of potential improper use of the system). The optical analyzer assembly and / or imaging device monitors images of the end face of the light guide at a high frame rate looking for non-zero states or predetermined changes in the signal over time. (3) The pulse generator sends a trigger to the light source (IR laser) to emit an energy pulse, which can be initiated, for example, by an operator pressing a start button. (4A) The image sensor subsystem does not detect light returning from the light guide signaling acceptable use parameters. (4B) The image sensor subsystem detects changes in the light returning from the light guide signaling externally emanating ambient light, which is an indication that the catheter system is being used unintended and sends a signal to the control electronics. (5A) If step (4A) is satisfied, the control electronics enables use of the light source by disabling safety interlocks and / or opening shutters that would otherwise interrupt the light source beam. Then proceed to step (6). (5B) If step (4B) is satisfied, the control electronics locks out the light source by activating a safety interlock and / or closing a shutter to stop or interrupt the light source beam, after which the process stops and does not proceed after the catheter is repositioned as necessary and / or returns to step (1). (6) A guide beam in the form of a first optical energy is focused onto the guide proximal end of the light guide and couples the pulse of IR energy therein. (7) A pulse of IR energy in the form of a first light energy travels through the light guide and excites the plasma generator, which creates a localized plasma in the balloon fluid within the balloon interior of the balloon. (8) The pulse of broad-spectrum light energy emitted from the plasma in the form of a second light energy is coupled back into the distal end of the light guide via the distal light receiver and returned through the light guide to the proximal end. (9) The beam splitter and optical elements cooperate to form an image of the end face of the light guide onto the photodetector. (10) The signal from the photodetector is amplified and can be used to determine the intensity of the plasma event. (11) The pulses from the amplified photodetector are conditioned and this information is used to determine when a plasma event occurs. (12) If no light pulse is detected at all, if a smaller light pulse is detected that occurs too soon relative to the energy pulse from the light source, or if the light pulse is detected to have a different spectrum or lack a spectral line or signature, this can be used to indicate a failure of the plasma generator, light source, light guide and / or the entire catheter system. (13) If (12) is satisfied, the control electronics will lock out the light source by activating a safety interlock and / or closing a shutter to stop or interrupt the light source beam, after which the process will be stopped and will not proceed.

[0146] Thus, as described above, the optical analyzer assembly 242 of the present invention addresses several potential challenges related to the performance, reliability, safety, and proper use of IVL catheters, particularly those that utilize an energy source, such as a laser source, to generate a localized plasma that induces high-energy bubbles in the balloon fluid 132 within the balloon interior 146 of the balloon 104. For example, as described above, challenges addressed by the present invention include, but are not limited to, 1) optically detecting when the IVL catheter is in place at the treatment site, 2) optically detecting conditions under which the IVL catheter may be misused, 3) optically detecting the successful firing of an energy source, such as a laser source, to generate plasma within the balloon interior, 4) accurately determining the energy output of the plasma generator, 5) optically detecting failure of the catheter system to generate the desired plasma within the balloon interior, and 6) optically detecting failure of the energy guide at any point along its length.

[0147] The remaining figures are provided to further illustrate and explain certain features and aspects of the present invention with respect to the operation and analysis of the optical analyzer assembly and the subsequent determination of operating conditions within the catheter system.

[0148] Figures 3A-3F are simplified schematic diagrams of operating states that may be identified by the optical analyzer assembly during operation of the catheter system of Figure 1. More specifically, Figure 3A is a simplified schematic diagram of a first operating state 388A that may be identified by the optical analyzer assembly during operation of the catheter system, Figure 3B is a simplified schematic diagram of a second operating state 388B that may be identified by the optical analyzer assembly during operation of the catheter system, Figure 3C is a simplified schematic diagram of a third operating state 388C that may be identified by the optical analyzer assembly during operation of the catheter system, Figure 3D is a simplified schematic diagram of a fourth operating state 388D that may be identified by the optical analyzer assembly during operation of the catheter system, Figure 3E is a simplified schematic diagram of a fifth operating state 388E that may be identified by the optical analyzer assembly during operation of the catheter system, and Figure 3F is a simplified schematic diagram of a sixth operating state 388F that may be identified by the optical analyzer assembly during operation of the catheter system.

[0149] 3A, a first operating state 388A shows the light guide 322A and plasma generator 333 in a normal operating state. In such a normal operating state, first optical energy 324B is directed from the distal guide end 322D of the light guide 322A toward the plasma generator 333, thereby impinging on the target surface 333T of the plasma generator 333, generating a plasma 334 and subsequent acoustic waves (shown as a series of arc lines) substantially immediately adjacent to the plasma generator 333.

[0150] In FIG. 3B, the light guide 322A and plasma generator 333 are shown in a second operating state 388B in which an intermittent bubble-generation state exists. In such second operating state 388B, bubbles 389 (one bubble 389 is shown in FIG. 3B) formed in the balloon fluid 132 (shown in FIG. 1) are found between the guide distal end 322D of the light guide 322A and the plasma generator 333, which optically affect the direction of the first light energy 324B toward the target surface 333T of the plasma generator 333. Thus, little or no plasma (not shown in FIG. 3B) is generated, and the resulting flash signature may have a lower pulse maximum than desired for most effectively destroying the vascular lesion 106A (shown in FIG. 1) at the treatment site 106 (shown in FIG. 1). Under such conditions, the operator can shut down operation of the catheter system 100 (shown in FIG. 1) and service the fluid pump 138 (shown in FIG. 1) and / or inflation conduit 140 (shown in FIG. 1) to suppress the creation of such intermittent bubbles 389 without having to replace the light guide 322A and / or the plasma generator 333.

[0151] In FIG. 3C , the light guide 322A and plasma generator 333 are shown in a third operating state 388C in which a guide distal end plasma initiation condition exists. In such third operating state 388C, there may be some debris substantially adjacent to the guide distal end 322D of the light guide 322A, causing the plasma 334 and subsequent acoustic waves (shown as a series of arc lines) to be generated at such a point substantially adjacent to the guide distal end 322D of the light guide 322A, rather than substantially directly adjacent to the plasma generator 333. The resulting flash signature may have a higher pulse maximum than under baseline conditions. This may also affect the ability of the catheter system 100 (shown in FIG. 1 ) to most effectively destroy the vascular lesion 106A (shown in FIG. 1 ) at the treatment site 106 (shown in FIG. 1 ). However, the third operating state 388C shuts down operation of the catheter system 100 so that such areas within the balloon 104 (shown in FIG. 1) can be cleaned by subsequent flushing without the need to replace the light guide 322A and / or the plasma generator 333.

[0152] In FIG. 3D , the light guide 322A is shown in a fourth operating state 388D in which a housing / target failure condition exists. In such fourth operating state 388D, the first light energy 324B directed by the light guide 322A cannot generate the desired plasma flash in the balloon fluid 132 (shown in FIG. 1 ) within the balloon interior 146 (shown in FIG. 1 ). Under such conditions, the resulting flash signature has a lower pulse maximum. This provides evidence that there is a failure of the light guide 322A and / or the plasma generator 333 (e.g., shown in FIG. 3A ) in the process of generating the desired plasma flash to effectively destroy the vascular lesion 106A (shown in FIG. 1 ) at the treatment site 106 (shown in FIG. 1 ). Therefore, to correct or overcome this condition, the catheter system 100 (shown in FIG. 1 ) can be taken out of service, and the light guide 322A and / or the plasma generator 333 can be removed and replaced, or the catheter system 100 can be discarded entirely. Note that plasma generator 333 is not shown in FIG. 3D to more clearly illustrate the failure to generate the desired plasma.

[0153] In FIG. 3E, the light guide 322A is shown in a fifth operating state 388E in which a broken light guide (fiber) condition exists. In such a fifth operating state 388E, little or no plasma (not shown in FIG. 3E) is generated in the balloon fluid 132 (shown in FIG. 1) within the balloon interior 146 (shown in FIG. 1), and any minimal plasma that does occur typically has a lower pulse maximum because the first light energy 324B is directed in multiple different directions away from the distal guide end 322D of the light guide 322A rather than directly toward the plasma generator 333 (e.g., shown in FIG. 3A). It is understood that this failure mode can occur anywhere along the length of the catheter, not just within the balloon. When such a fifth operating state 388E is determined to exist, operation of the catheter system 100 (shown in FIG. 1) should be stopped.

[0154] In FIG. 3F , the light guide 322A and plasma generator 333 are shown in a sixth operating state 388F in which a chewback condition exists, such as a broken light guide 322A at least some distance from the guide distal end 322D along the length of the light guide 322A. In such a sixth operating state 388F, generation of plasma 334 (shown as a series of arcuate lines) may occur in the balloon fluid 132 (shown in FIG. 1 ) within the balloon interior 146 (shown in FIG. 1 ) substantially adjacent to the location of the potential break along the length of the light guide 322A. Under such conditions, the resulting flash signature is typically very sawtooth-like, increasing and decreasing in magnitude very rapidly over time. If such a sixth operating state 388F is determined to exist, the generated plasma 334 is much less likely to be directed in an appropriate manner to effectively destroy the vascular lesion 106A (shown in FIG. 1 ) at the treatment site 106 (shown in FIG. 1 ). Therefore, operation of the catheter system 100 (shown in FIG. 1 ) should be stopped.

[0155] As provided herein, many of the analyses performed through the use of an optical analyzer assembly involve capturing an image of a flash signal (or flash signature) resulting from plasma generation in the balloon fluid within the balloon interior, and subsequently analyzing the flash signal (or flash signature) as a means of determining the operating state of the catheter system. It is understood that the flash signal (or flash signature) can take any particular form, and there are infinite possibilities for all the details incorporated into the flash signal (or flash signature). Figures 4A and 4B provide simplified graphical illustrations of two potential examples of what a flash signal (or flash signature) may look like when captured through the use of an optical analyzer assembly.

[0156] 4A is a simplified graphical illustration of a representative example of a first flash signature 490A that may be identified by the optical analyzer assembly 242 (e.g., shown in FIG. 2A) during operation of the catheter system 100 of FIG. 1 in terms of flash intensity (Y-axis) versus time (X-axis). More specifically, the first flash signature 490A is identified by the optical analyzer assembly 242 during the generation of a plasma flash 334 (shown in FIG. 3A) from a single pulse of first light energy 324B (shown in FIG. 3A) from the light source 124 (shown in FIG. 1) through the light guide 322A (shown in FIG. 3A). As shown, the first flash signature 490A has a single peak 491A and two transitions 492A. In analyzing the peaks of any given flash signature, the maximum or highest peak may be referred to as the “pulse maximum intensity” value or simply the “pulse maximum.” In FIG. 4A, first flash signature 490A has only a single peak 491A, which is also referred to as the pulse maximum intensity value or "pulse maximum."

[0157] 4B is a simplified graphical illustration of a representative example of a second flash signature 490B that may be identified by the optical analyzer assembly 242 (e.g., shown in FIG. 2A) during operation of the catheter system 100 of FIG. 1, with respect to flash intensity (Y-axis) versus time (X-axis). More specifically, the second flash signature 490B is identified by the optical analyzer assembly 242 during the generation of a plasma flash 334 (shown in FIG. 3A) from a single pulse of first light energy 324B (shown in FIG. 3A) from the light source 124 (shown in FIG. 1) through the light guide 322A (shown in FIG. 3A). As shown, the second flash signature 490B has three peaks 491B and six transitions 492B. Again, in analyzing the peaks of any given flash signature, the highest peak may be referred to as the “pulse maximum intensity” value or simply the “pulse maximum.” In FIG. 4B, the second flash signature 490B has three peaks 491B, the first peak 491B being the largest or highest, and therefore also referred to as the pulse maximum intensity value or "pulse maximum."

[0158] As referred to herein, a "transition" is generally defined as a change in the direction of the slope of the flash signature as shown in a graphical diagram. As shown in Figures 4A and 4B, both signals have a transition when the signal rises rapidly from the x-axis. Both signals also have another transition when the signal falls from the pulse maximum. Figure 4B has more transitions or variability in the signal from this point onwards. The exact number of transitions measured in each signal depends on the adjustment of various parameters. One parameter defines the magnitude of the slope change required to classify something as a transition, and the other is a history parameter to avoid counting noise transitions in the signature.

[0159] Figure 5 is a simplified graphical illustration 593 of an example of maximum pulse intensity readings that may be identified by the optical analyzer assembly from the plasma flash generated when a pulse of first optical energy is sent through a light guide used in the catheter system of Figure 1. As shown, the maximum pulse intensity reading (in arbitrary units) from the plasma flash generated for each pulse of first optical energy being guided through the light guide is shown along the Y-axis, and the pulse number for a particular light guide is shown along the X-axis. Stated another way, the Y-axis relates to the maximum value found in the flash signature (or flash signal) detected by the optical analyzer assembly for any given pulse of first optical energy sent through a given light guide.

[0160] FIG. 5 shows both a minimum pulse maximum intensity threshold 594 and a maximum pulse maximum intensity threshold 595 that may be used by the system controller to help define the operating conditions of the light guide and / or plasma generator.

[0161] The minimum pulse maximum intensity threshold 594 may be used by the system controller to determine whether the light guide operating condition is one of an intermittent bubble generation condition, a housing / target failure condition, and / or a broken light guide (fiber) condition. In any of such operating conditions, the pulse maximum intensity has a low value that provides an indication that the plasma flash, if any, may not be sufficient to effectively destroy vascular lesions at the treatment site.

[0162] It is understood that a pulse maximum intensity value at or very close to zero is an indication of any of the conditions described in the previous paragraph, where little or no plasma flash has occurred. Because of this ambiguity in potential failure modes, instead of responding to a single instance of a no-signal condition, the history of all pulses on each fiber can be tracked to distinguish such conditions. As explained further below, the pulse maximum intensity value does not necessarily have to be zero to indicate such a failure condition, since it is always possible that at least some extraneous light can be captured by the distal optical receiver and transmitted back from the distal guide end toward the proximal guide end as second optical energy.

[0163] In one non-exclusive embodiment, minimum pulse maximum intensity threshold 594 may be approximately 100 units, such that any recorded pulse maximum intensity value of 100 units or less may indicate such an undesirable operating condition of the light guide. Alternatively, in other embodiments, minimum pulse maximum intensity threshold 594 may be approximately 50 units, 75 units, 125 units, 150 units, 175 units, 200 units, or another suitable minimum pulse maximum intensity threshold.

[0164] As will be further described below in connection with FIG. 7, to avoid potential false positive readings of no signal conditions, it will be appreciated that for true positive identification of such no signal conditions, it may be desirable to require a certain number of pulses of the first light energy to have a pulse maximum intensity value below a pulse maximum intensity threshold without signal detection, such as 50 units in one non-exclusive embodiment, within a certain range or number of pulses of the first light energy.

[0165] The maximum pulse maximum intensity threshold 595 may be used by the system controller to determine whether the operating state of the light guide is a guide distal end plasma initiation state. Under such conditions, the maximum pulse intensity of the plasma flash when secondary light energy is transmitted back through the light guide and optically analyzed by the optical analyzer assembly may be higher than under normal operating conditions because the plasma flash is often larger and occurs substantially immediately adjacent to the guide distal end of the light guide. Simply stated, under such conditions, more secondary light energy is received by the distal light receiver and therefore transmitted back through the light guide in the second direction because such light energy is generated and / or reflected substantially immediately adjacent to the guide distal end and thus the distal light receiver.

[0166] In one non-exclusive embodiment, maximum pulse maximum intensity threshold 595 may be approximately 1000 units, such that any recorded pulse maximum intensity value of 1000 units or greater may indicate such an undesirable operating condition of the light guide. Alternatively, in other embodiments, maximum pulse maximum intensity threshold 595 may be approximately 900 units, 925 units, 950 units, 975 units, 1025 units, 1050 units, 1075 units, 1100 units, 1125 units, 1150 units, or another suitable maximum pulse maximum intensity threshold.

[0167] 5 further illustrates typical pulse maximum intensity values, i.e., normal pulse maximum intensity range 596, of the plasma flash when the light guide is operating under normal operating conditions. In one non-exclusive embodiment, a normal operating condition may be determined if normal pulse maximum intensity range 596 is between approximately 300 units and 800 units. Alternatively, the normal pulse maximum intensity range 596 for indication of a normal operating condition may vary from the ranges described above, so long as such normal pulse maximum intensity range 596 does not overlap or exceed (i.e., below) a minimum pulse maximum intensity threshold 594 or exceed (i.e., above) a maximum pulse maximum intensity threshold 595. For example, in certain non-exclusive alternative embodiments, the normal pulse maximum intensity range 596 of the plasma flash may be between approximately 200 units and 900 units, such as between approximately 250 units and 850 units, between approximately 350 units and 900 units, between approximately 300 units and 850 units, or some other range of suitable pulse maximum intensity values.

[0168] FIG. 6 is a simplified graphical illustration 693 of an example number of transitions that may be identified by the optical analyzer assembly in a flash signal generated when a pulse of first optical energy is sent through a light guide used in the catheter system of FIG. 1 . As shown, the number of transitions identified in the flash signature (or flash signal) of the light guide for any given pulse of first optical energy is shown along the Y-axis, and the pulse number of the particular light guide is shown along the X-axis. FIG. 6 provides an indication that the light guide may be suffering from chewback if the number of transitions in the plasma signature for any given pulse of first optical energy exceeds a particular transition threshold 697. In one embodiment, as shown, the transition threshold 697 for identifying the light guide as suffering from chewback may be six transitions. Alternatively, in other embodiments, the transition threshold 697 for identifying the light guide as suffering from chewback may be four transitions, five transitions, seven transitions, eight transitions, nine transitions, ten transitions, or another suitable number of transitions.

[0169] It is understood that to avoid potential false positive readings for identifying the Chewback state, it may be desirable to require a certain number of pulses of first light energy to have a number of transitions that is greater than or equal to the transition threshold 697 for a true positive identification of the Chewback state. For example, in one non-exclusive embodiment, it may be necessary to find at least three pulses of first light energy with a number of transitions that is greater than or equal to the transition threshold to unambiguously identify the Chewback state. Alternatively, in other embodiments, it may be necessary to find only one, or at least two, four, five, six, or some other suitable number of pulses of first light energy with a number of transitions that is greater than or equal to the transition threshold to unambiguously identify the Chewback state.

[0170] Figure 7 is a simplified graphical illustration 793 of one example of how a no-signal detection condition may be identified by the optical analyzer assembly when a pulse of first light energy is sent through a light guide used in the catheter system of Figure 1. Similar to Figure 5, the maximum pulse intensity reading (in arbitrary units) from the plasma flash occurs for each pulse of first light energy guided through the light guide and is shown along the Y-axis, and the pulse number for a particular light guide is shown along the X-axis. Stated another way, the Y-axis relates to the highest peak seen in the flash signature (or flash signal) detected by the optical analyzer assembly for any given pulse of first light energy sent through a given light guide.

[0171] 7 illustrates a zero threshold 798 (or no-signal detection threshold) and a window zero count 799 (or no-signal detection range). In order to effectively establish a no-signal detection condition (and / or avoid inappropriately identifying such a condition), various embodiments may require finding a specific number of pulses (or zero pulse count) within the window zero count 799 (a given number or range of preceding pulses) that have a pulse maximum intensity value below the zero threshold 798. Stated another way, if the number of pulses within the window zero count 799 prior to the first pulse of light energy through a given light guide that has a pulse maximum intensity value below the zero threshold 798 meets or exceeds the zero pulse count, the system effectively identifies a no-signal detection condition.

[0172] It is understood that the zero threshold 798, window zero count 799, and zero pulse count may all be varied in the process of attempting to clearly identify a no signal detected condition. For example, in one non-exclusive embodiment, the zero threshold 798 may be established when the pulse maximum intensity value of a given pulse of light energy passing through the light guide is less than or equal to 50 units. Alternatively, in other embodiments, the zero threshold 798 may be established where the pulse maximum intensity value is less than or equal to 10 units, 15 units, 20 units, 25 units, 30 units, 35 units, 40 units, 45 units, 55 units, 60 units, 65 units, 70 units, 75 units, or some other suitable number of units.

[0173] In one non-exclusive embodiment, window zero count 799 can refer to a range of 20 pulses within which a defined zero pulse count of pulses of first light energy sent through a given light guide must have a reading below zero threshold 798 to effectively identify a no signal detected condition. Alternatively, in other embodiments, window zero count 799 can refer to a range of 15 pulses, 16 pulses, 17 pulses, 18 pulses, 19 pulses, 21 pulses, 22 pulses, 23 pulses, 24 pulses, 25 pulses, 26 pulses, 27 pulses, 28 pulses, 29 pulses, 30 pulses, 31 pulses, 32 pulses, 33 pulses, 34 pulses, 35 pulses, 36 pulses, 37 pulses, 38 pulses, 39 pulses, 40 pulses, or another suitable number of pulses within which a defined zero pulse count of pulses of first light energy sent through a given light guide must have a reading below zero threshold 798 to effectively identify a no signal detected condition. As used herein, the window zero count 799 is specifically the number of previous pulses to look at for a given light guide when determining a no signal detection condition, rather than considering the entire history of the light guide.

[0174] In one non-exclusive embodiment, the defined zero pulse count can be 11 pulses of first light energy being sent through a given light guide having a reading below the zero threshold 798 within the window zero count 799 range to effectively identify a no signal detected condition. Alternatively, the defined zero pulse count can be 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, or any other suitable number of pulses of first light energy being sent through a given light guide having a reading below the zero threshold 798 within the window zero count 799 range to effectively identify a no signal detected condition.

[0175] In one specific, non-exclusive embodiment, where the zero threshold is 50 units, the window zero count is 20 pulses and the defined zero pulse count is 11 pulses. Then, to effectively determine the no signal detection condition, one must find at least 11 pulses of first light energy through a given light guide within the preceding 20 pulses that have a pulse maximum intensity value less than the zero threshold of 50 units.

[0176] It will be appreciated that the present invention can be used to monitor the position and status of any device that uses an optical light source and light guide for energy transmission. One alternative example is nephrolithotomy using laser lithotripsy. Specifically, a beam splitter and optical system incorporating the present invention can be incorporated into a lithotripsy laser system. This allows for continuous monitoring of light in the form of a second optical energy returning from the distal end of the lithotripsy light guide. Once the light guide is inserted into the kidney through the nephroscope, the ambient lighting conditions are controlled by the nephroscope illumination. The characteristics and spectrum of the detected light can be used to determine whether the light guide is properly positioned inside the kidney and whether it is safe to emit the light source. One means of achieving this is to use a signal source with specific wavelength characteristics in the scope illumination. For example, this could include a high-intensity narrowband light source that is not present in the external ambient light. This can be detected using a bandpass filter in front of the photodetector. The light source is locked out until its optical signal is detected, preventing it from emitting hazardous laser radiation outside the patient.

[0177] In summary, the catheter system and related methods disclosed herein are configured to monitor the safety, performance, reliability, and proper use of intravascular lithotripsy (IVL) catheters. In various embodiments, the catheter system of the present invention utilizes an energy source, e.g., a light source such as a laser source, or another suitable energy source that provides energy guided by an energy guide, e.g., a light guide, to create a localized plasma in the balloon fluid within the balloon interior of the catheter's inflatable balloon. Thus, the energy guide may be referred to as or incorporate a "plasma generator" at or near the distal end of the energy guide, which is positioned within the balloon interior. This localized plasma generates pressure waves that apply pressure to a treatment site within or adjacent to a blood vessel or heart valve within the patient's body, inducing spallation. As used herein, a treatment site may include a vascular lesion, such as a calcified or fibrous vascular lesion, typically found in blood vessels and / or heart valves.

[0178] In particular, in various embodiments, a catheter system can include a catheter configured to advance to a treatment site within or adjacent to a blood vessel or heart valve within a patient's body. The catheter includes a catheter shaft and a balloon coupled to and / or secured to the catheter shaft. The balloon can include a balloon wall defining a balloon interior and can be configured to receive balloon fluid within the balloon interior to expand from a deflated state suitable for advancing the catheter through the patient's vasculature to an inflated state suitable for securing the catheter in position relative to the treatment site. The catheter system also includes one or more energy guides disposed within the balloon along the catheter shaft. Each energy guide can be configured to generate pressure waves within the balloon to destroy vascular lesions.

[0179] The catheter system utilizes energy from an energy source, such as first light energy from a light source, to generate plasma, such as via a plasma generator, within balloon fluid at or near the distal end of an energy guide disposed within a balloon located at a treatment site. The formation of the plasma can initiate one or more pressure waves and the rapid formation of one or more bubbles, which can rapidly expand to a maximum size and then dissipate via a cavitation event, which can emit pressure waves upon collapse. The rapid expansion of the plasma-induced bubbles can generate one or more pressure waves within the balloon fluid held within the balloon, thereby imparting pressure waves to the treatment site. In some embodiments, the energy source can be configured to provide submillisecond pulses of energy from the energy source to initiate plasma formation in the balloon fluid within the balloon, causing rapid bubble formation and imparting pressure waves to the balloon wall at the treatment site. The pressure waves can thus transfer mechanical energy to the treatment site via the incompressible balloon fluid, imparting a disruptive force to the treatment site.

[0180] As described in detail herein, the catheter system of the present invention includes an optical analyzer assembly configured to provide real-time continuous monitoring of the energy emitted from the distal end of the energy guide into the balloon interior. The optical analyzer assembly can be used to detect the occurrence of plasma events and monitor the nominal operation of the catheter system. The optical analyzer assembly is further configured to monitor the ambient energy received at the distal end of the energy guide and can be used as a monitor for proper use and positioning of the catheter system. For example, monitoring the ambient energy from the distal end of the energy guide, starting from the plasma generator, can be used to detect the overall state and condition of the device as a monitor for nominally safe operation. Similarly, measuring changes in the intensity of the conducted energy over a time interval provides an indication of the location of the distal end and the plasma generator itself. When located inside the human body, the ambient energy conducted through the energy guide is minimal. This is zero, and any baseline is expected to be minimally variable. Conversely, when the device is located outside the human body, the conducted energy is not zero but varies significantly. This information can be used to determine the location of the distal end of the energy guide. This can be used to assess the state of the energy guide and determine if the device is nominally functioning.

[0181] The optical analyzer assembly can also be utilized to measure the intensity of energy emitted from the energy guide to provide an accurate measurement of the energy output of a plasma generator incorporated as part of and / or used in combination with the energy guide. More specifically, measurements of the energy output of the plasma generator can be used in conjunction with a known energy input from an energy source to determine conversion efficiency. Such metrics can also be used to assess the status of the plasma generator and energy guide and determine whether the catheter system is operating normally and the number of operating cycles remaining.

[0182] In particular, in various embodiments, the present invention includes means for sampling the second optical energy returned from the plasma generator and / or from the interior of the balloon through the energy guide. It is understood that the energy can travel in both opposing directions along the length of the energy guide. Thus, it is possible to detect energy originating at the proximal guide end of the energy guide, at the distal guide end of the energy guide, or at any other location along the length of the energy guide. Thus, such second optical energy returned through the energy guide can be isolated and detected and / or analyzed via the optical analyzer assembly to effectively monitor the safety, performance, reliability, and proper use of the catheter system.

[0183] It will be appreciated that continuous monitoring of the energy emitted from the plasma generator and measuring the intensity of the emitted energy through the use of the present invention addresses several potential challenges related to the safety, performance, reliability, and proper use of IVL catheters, particularly the challenge of utilizing an energy source to create a localized plasma that generates high-energy bubbles within the balloon catheter. Specific challenges addressed by the present invention include: 1) optically detecting when the IVL catheter is in place at the treatment site, 2) optically detecting conditions under which the IVL catheter may be misused, 3) optically detecting the successful firing of an energy source, such as a laser source, to generate plasma within the balloon, 4) accurately determining the energy output of the plasma generator, 5) optically detecting failure of the catheter system to generate the desired plasma within the balloon, and 6) optically detecting failure of the energy guide at any point along its length.

[0184] It will be further appreciated that the optical analyzer assembly may be configured to automatically shut down operation of the catheter system if improper use or failure of the catheter system is detected and / or if a failure of the energy guide is detected at any point along the length of the energy guide. Accordingly, in various embodiments, the catheter system and / or the optical analyzer assembly may incorporate and / or include a safety shutdown system that may be selectively activated when it is necessary to automatically shut down operation of the catheter system. In some such embodiments, the safety shutdown system may include one or more of a safety interlock, a shutter, and / or other suitable safety shutdown mechanism that may be incorporated into the optical analyzer assembly. With such a design, the optical analyzer assembly is uniquely configured to mitigate dangerous conditions for the patient and the operator of the catheter system.

[0185] It should be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content and / or context clearly dictates otherwise. It should also be noted that the term "or" is generally used in its sense including "and / or" unless the content or context clearly dictates otherwise.

[0186] It should also be noted that, as used herein and in the appended claims, the phrase "configured" describes a system, apparatus, or other structure that is constructed or arranged to perform a particular task or adopt a particular configuration. The phrase "configured" can be used interchangeably with other similar phrases such as arranged and configured, constructed and arranged, constructed, manufactured and arranged, etc.

[0187] The headings used herein are provided for consistency with suggestions under 37 CFR 1.77 or to otherwise provide an organizational cue. These headings should not be construed as limiting or characterizing the invention(s) set forth in any claimed invention(s) that may issue from this disclosure. As an example, a description of technology in the "Background" section is not an admission that that technology is prior art to any invention(s) in this disclosure. Neither the "Summary" nor the "Abstract" should be construed as a feature of the invention(s) set forth in the issued claims.

[0188] The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the detailed description provided herein. Rather, the embodiments are chosen and described so that those skilled in the art can appreciate and understand the principles and practices. Accordingly, aspects have been described with reference to various specific preferred embodiments and techniques. However, it should be understood that many variations and modifications can be made while remaining within the spirit and scope of the description.

[0189] Although several different embodiments of the catheter system have been shown and described herein, it should be understood that one or more features of any one embodiment may be combined with one or more features of one or more of the other embodiments, provided such combinations meet the intent of the present invention.

[0190] While several exemplary aspects and embodiments of the catheter system have been described above, those skilled in the art will recognize certain modifications, permutations, additions, and sub-combinations thereof. Accordingly, the following appended claims and the claims introduced below are intended to be interpreted to include all such modifications, permutations, additions, and sub-combinations as fall within their true spirit and scope, and are not intended to limit the details of construction or design shown herein. The technical concepts that can be understood from the above-described embodiment will be described below as supplementary notes. (Appendix 1) 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, comprising: a light source that generates a first light energy; a balloon positionable substantially adjacent the treatment site, the balloon having a balloon wall defining a balloon interior, the balloon interior receiving a balloon fluid; a light guide configured to receive first light energy at a guide proximal end and guide the first light energy in a first direction from the guide proximal end toward a guide distal end positioned within the balloon interior; an optical analyzer assembly configured to optically analyze second light energy from the light guide traveling in a second direction opposite the first direction, the optical analyzer assembly including a safety shutdown system selectively activated to prevent the first light energy from the light source from being received by the guide proximal end of the light guide; A catheter system comprising: (Appendix 2) 2. The catheter system of claim 1, further comprising a pulse generator coupled to the light source, the pulse generator configured to trigger the light source to generate a light source beam that is directed toward the light guide. (Appendix 3) 3. The catheter system of claim 2, wherein the safety shutdown system includes a safety interlock that is selectively activated to prevent the pulse generator from triggering generation of the light source beam using the light source. (Appendix 4) 4. The catheter system of claim 2, wherein the safety shutdown system includes a shutter that is selectively activated to prevent the light source beam from being directed toward the light guide. (Appendix 5) 5. The catheter system according to claim 1, wherein the first light energy induces plasma generation inside the balloon. (Appendix 6) 6. The catheter system of claim 5, wherein the guide distal end includes a distal light receiver that receives the second light energy from within the balloon interior, and the second light energy travels through the light guide in the second direction. (Appendix 7) 7. The catheter system of claim 6, wherein the second light energy received by the distal light receiver is emitted from plasma generated in the balloon fluid within the interior of the balloon. (Appendix 8) 7. The catheter system of claim 6, wherein the second light energy received by the distal light receiver is from ambient light near the distal end of the light guide. (Appendix 9) 9. The catheter system of claim 6, wherein the second optical energy received by the distal optical receiver is optically analyzed by the optical analyzer assembly. (Appendix 10) 10. The catheter system of claim 9, wherein the optical analyzer assembly is configured to optically determine whether plasma generation has occurred within the balloon interior. (Appendix 11) 11. The catheter system of any one of claims 9 to 10, wherein the optical analyzer assembly is configured to optically detect a fault in the light guide between the proximal guide end and the distal guide end. (Appendix 12) 12. The catheter system of any one of claims 9 to 11, wherein the optical analyzer assembly is configured to optically detect potential damage to the optical guide between the proximal guide end and the distal guide end. (Appendix 13) 13. The catheter system of any one of claims 10 to 12, wherein the optical analyzer assembly is configured to selectively activate the safety shutdown system upon optical detection by the optical analyzer assembly of any one of (i) failure to generate plasma within the balloon interior, (ii) failure of the optical guide between the proximal guide end and the distal guide end, and (iii) potential damage to the optical guide between the proximal guide end and the distal guide end. (Appendix 14) 6. The catheter system of claim 5, wherein the second light energy is guided in the second direction back through the light guide toward the proximal end of the guide, and the optical analyzer assembly is configured to optically analyze the second light energy to determine whether plasma generation has occurred within the balloon. (Appendix 15) 15. The catheter system of claim 14, wherein the optical analyzer assembly includes a beam splitter and a photodetector, the beam splitter configured to receive the second optical energy and direct a portion of the second optical energy to the photodetector. (Appendix 16) 16. The catheter system of claim 15, wherein the optical analyzer assembly further includes an optical element positioned along a beam path between the beam splitter and the photodetector, the optical element configured to couple the portion of the second light energy to the photodetector. (Appendix 17) 17. The catheter system of claim 16, wherein the optical analyzer assembly further includes a second beam splitter positioned along the beam path between the beam splitter and the optical detector, the second beam splitter configured to receive the second optical energy and direct at least a portion of the portion of the second optical energy to the optical detector. (Appendix 18) 18. The catheter system of any one of claims 15 to 17, wherein the photodetector generates a signal based at least in part on visible light contained in the portion of the second light energy. (Appendix 19) 19. The catheter system of claim 18, wherein the signal from the photodetector is amplified with an amplifier to provide an amplified signal that is directed to control electronics to determine an intensity of the plasma generation within the balloon. (Appendix 20) 20. The catheter system of claim 19, wherein the control electronics are configured to analyze the amplified signal to detect one or more of: (i) whether plasma generation has occurred within the balloon interior; (ii) potential failure of the optical guide between the proximal guide end and the distal guide end; and (iii) potential damage to the optical guide between the proximal guide end and the distal guide end. (Appendix 21) 21. The catheter system of any one of claims 1 to 20, wherein the optical analyzer is configured to optically analyze the second light energy to detect an operating state of the catheter system. (Appendix 22) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least one of (i) a normal operating condition, (ii) an intermittent gas bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a poor plasma generation condition, (v) a broken light guide condition, and (vi) a chewback condition. (Appendix 23) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least two of: (i) a normal operating condition; (ii) an intermittent gas bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition. (Appendix 24) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least three of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition. (Appendix 25) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least four of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition. (Appendix 26) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least five of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a broken light guide condition; and (vi) a chewback condition. (Appendix 27) 22. The catheter system of claim 21, wherein the optical analyzer is configured to optically analyze the second light energy to detect each of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a poor plasma generation condition, (v) a broken light guide condition, and (vi) a chewback condition. (Appendix 28) 28. The catheter system of any one of claims 22 to 27, wherein the optical analyzer assembly can be further configured to stop operation of the catheter system upon detecting one or more of a plasma generation failure condition, a light guide breakage condition, and a chewback condition. (Appendix 29) 29. The catheter system of any one of claims 21 to 28, wherein the first pulse of light energy directed through the light guide in the first direction produces a plasma flash that can be captured by the optical analyzer assembly in the form of a flash signature that can provide an indication of the operational state of the catheter system and can include summary parameters such as at least one of pulse maximum, rise time, width, onset time relative to a baseline, and a measure of signal variability. (Appendix 30) 30. The catheter system of claim 29, wherein the optical analyzer assembly is capable of identifying the operating condition as a guide distal end plasma initiation condition if the pulse maximum value of the flash signature is greater than a maximum pulse maximum threshold. (Appendix 31) 30. The catheter system of claim 29, wherein the optical analyzer assembly is capable of identifying the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition when the pulse maximum value of the flash signature is less than a minimum pulse maximum threshold. (Appendix 32) 32. The catheter system of claim 31, wherein the optical analyzer assembly is configured to require that the number of pulses of first light energy in which the pulse maximum of the flash signature is less than a minimum pulse maximum threshold within a specified range of previous pulses exceed a defined zero pulse count to identify the operating condition as one of an intermittent gas bubble condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 33) 33. The catheter system of claim 32, wherein a history of all pulses of first light energy directed in the first direction through the light guide is tracked to distinguish between the intermittent bubble generation condition, the poor plasma generation condition, and the light guide damage condition. (Appendix 34) 30. The catheter system of claim 29, wherein the measure of signal variability of the flash signature comprises a number of transitions identified in the flash signature. (Appendix 35) 35. The catheter system of claim 34, wherein the optical analyzer assembly is capable of identifying the operating state as a Chewback state if the number of transitions in the flash signature is greater than a transition threshold. (Appendix 36) 2. The catheter system of claim 1, wherein the guide distal end includes a distal light receiver that receives the second light energy from within the balloon interior, and the second light energy travels through the light guide in the second direction. (Appendix 37) 37. The catheter system of claim 36, wherein the second light energy received by the distal light receiver is from ambient light near the distal end of the light guide. (Appendix 38) 38. The catheter system of claim 37, wherein the optical analyzer assembly is configured to optically analyze the second light energy to determine whether ambient light is collected near the guide distal end of the light guide. (Appendix 39) 39. The catheter system of claim 38, wherein the optical analyzer assembly includes a beam splitter and an imaging device, the beam splitter configured to receive the second light energy and direct a portion of the second light energy to the imaging device. (Appendix 40) 40. The catheter system of claim 39, wherein the optical analyzer assembly further includes an optical element positioned along a beam path between the beam splitter and the imaging device, the optical element configured to couple the portion of the second light energy to the imaging device. (Appendix 41) 41. The catheter system of claim 40, wherein the optical analyzer assembly further includes a second beam splitter positioned along the beam path between the beam splitter and the imaging device, the second beam splitter configured to receive the second optical energy and direct at least a portion of the portion of the second optical energy onto the imaging device. (Appendix 42) 42. The catheter system of any one of claims 39 to 41, wherein the imaging device generates a signal based at least in part on any ambient light included in the portion of the second light energy. (Appendix 43) 43. The catheter system of claim 42, wherein the signal from the imaging device is directed to control electronics to determine whether ambient light is collected near the distal end of the light guide. (Appendix 44) 44. The catheter system of claim 43, wherein a determination by the control electronics that ambient light is collected near the distal end of the light guide is an indication that the catheter system is being used in an improper manner with the balloon not positioned substantially adjacent to the treatment site. (Appendix 45) 45. The catheter system according to any one of claims 1 to 44, wherein the light source includes a laser. (Appendix 46) 46. ​​The catheter system of any one of claims 1 to 45, wherein the light source includes an infrared laser that emits the first light energy in the form of pulses of infrared light. (Appendix 47) 47. The catheter system of any one of claims 1 to 46, wherein the light guide comprises an optical fiber. (Appendix 48) 1. A method of treating a treatment site within or adjacent to a blood vessel wall or heart valve, comprising: generating a first light energy using a light source; positioning a balloon substantially adjacent the treatment site, the balloon having a balloon wall defining a balloon interior, the balloon interior receiving a balloon fluid; receiving the first light energy at a guide proximal end of a light guide; guiding the first light energy in a first direction from the guide proximal end toward a guide distal end positioned within the balloon; optically analyzing second light energy from the light guide traveling in a second direction opposite the first direction, wherein an optical analyzer assembly includes a safety shutdown system selectively activated to prevent the first light energy from the light source from being received by the guide proximal end of the light guide; A method comprising: (Appendix 49) 49. The method of claim 48, further comprising coupling a pulse generator to the light source and triggering the light source to generate a light source beam directed toward the light guide using the pulse generator. (Appendix 50) 50. The method of claim 49, wherein the optically analyzing step includes selectively activating a safety interlock of the safety shutdown system to prevent the pulse generator from triggering the generation of the light source beam using the light source. (Appendix 51) 51. The method of any one of claims 49-50, wherein the optically analyzing step includes selectively activating a shutter of the safety shutdown system to prevent the light source beam from being directed toward the light guide. (Appendix 52) 52. The method of any one of claims 48-51, wherein the directing step includes the step of the first light energy inducing generation of plasma within the interior of the balloon. (Appendix 53) 53. The method of claim 52, wherein the guide distal end includes a distal optical receiver, and further comprising receiving the second optical energy from within the balloon interior using the distal optical receiver, wherein the second optical energy travels through the optical guide in the second direction. (Appendix 54) 54. The method of claim 53, wherein receiving the second light energy comprises receiving the second light energy by the distal light receiver from the plasma generated in the balloon fluid within the balloon interior. (Appendix 55) 54. The method of claim 53, wherein the step of receiving second light energy comprises receiving the second light energy by the distal light receiver from ambient light near the distal end of the light guide. (Appendix 56) 56. The method of any one of claims 53-55, wherein the optically analyzing step includes optically analyzing the second light energy received by the distal light receiver using the optical analyzer assembly. (Appendix 57) 57. The method of claim 56, wherein the optically analyzing step includes optically determining whether plasma generation has occurred within the balloon interior using the optical analyzer assembly. (Appendix 58) 58. The method of any one of claims 56-57, wherein the optically analyzing step includes optically detecting a fault in the light guide between the proximal guide end and the distal guide end with the optical analyzer assembly. (Appendix 59) 59. The method of any one of claims 56-58, wherein the optically analyzing step includes optically detecting potential damage to the light guide between the proximal guide end and the distal guide end using the optical analyzer assembly. (Appendix 60) 60. The method of any one of claims 57-59, wherein the optically analyzing step includes selectively activating the safety shutdown system upon optical detection by the optical analyzer assembly of any one of (i) failure of plasma generation within the balloon interior, (ii) failure of the optical guide between the proximal guide end and the distal guide end, and (iii) potential damage to the optical guide between the proximal guide end and the distal guide end. (Appendix 61) 53. The method of claim 52, further comprising guiding the second light energy back through the light guide in the second direction toward the guide proximal end, wherein optically analyzing comprises optically analyzing the second light energy with the optical analyzer assembly to determine whether plasma generation has occurred within the balloon interior. (Appendix 62) 62. The method of claim 61, wherein the optically analyzing step includes an optical analyzer assembly including a beam splitter and a photodetector, and further includes receiving the second light energy and directing a portion of the second light energy to the photodetector using the beam splitter. (Appendix 63) 63. The method of claim 62, wherein the optically analyzing step further comprises positioning an optical element along a beam path between the beam splitter and the photodetector, and coupling the portion of the second light energy to the photodetector using the optical element. (Appendix 64) 64. The method of claim 63, wherein the optically analyzing step further includes positioning a second beam splitter along the beam path between the beam splitter and the photodetector, and receiving the second optical energy and directing at least a portion of the portion of the second optical energy to the photodetector using the second beam splitter. (Appendix 65) 65. The method of any one of claims 62-64, wherein the step of optically analyzing further includes generating a signal using the photodetector based at least in part on visible light contained in the portion of the second light energy. (Appendix 66) 66. The method of claim 65, wherein the optically analyzing step further comprises amplifying the signal from the photodetector with an amplifier to provide an amplified signal, and directing the amplified signal to control electronics to determine an intensity of the plasma generation within the balloon. (Appendix 67) 67. The method of claim 66, wherein the optically analyzing step further includes analyzing the amplified signal using the control electronics to detect one or more of: (i) whether plasma generation has occurred within the balloon interior; (ii) potential failure of the optical guide between the proximal guide end and the distal guide end; and (iii) potential damage to the optical guide between the proximal guide end and the distal guide end. (Appendix 68) 68. The method of any one of claims 48-67, wherein the optically analyzing step includes optically analyzing the second light energy to detect an operating state of the catheter system. (Appendix 69) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least one of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a plasma failure condition, (v) a light guide broken condition, and (vi) a chewback condition. (Appendix 70) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least two of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 71) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least three of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 72) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least four of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 73) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least five of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 74) 69. The method of claim 68, wherein the optically analyzing step includes optically analyzing the second light energy to detect each of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a plasma failure condition, (v) a light guide breakage condition, and (vi) a chewback condition. (Appendix 75) 75. The method of any one of claims 69-74, further comprising the step of using the optical analyzer assembly to stop operation of the catheter system upon detecting one or more of a poor plasma generation condition, a broken light guide condition, and a chewback condition. (Appendix 76) 76. The method of any one of claims 68-75, further comprising directing the first pulse of light energy through the light guide in the first direction to generate a plasma flash that can be captured by the optical analyzer assembly in the form of a flash signature that can include summary parameters such as at least one of pulse maximum, rise time, width, onset time relative to a baseline, and a measure of signal variability that can provide an indication of the operational state of the catheter system. (Appendix 77) 77. The method of claim 76, wherein the optical analyzer assembly can identify the operating condition as a guide distal end plasma initiation condition if the pulse maximum value of the flash signature is greater than a maximum pulse maximum threshold. (Appendix 78) 77. The method of claim 76, wherein if the pulse maximum value of the flash signature is less than a minimum pulse maximum threshold, the optical analyzer assembly can identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 79) 79. The method of claim 78, wherein the optical analyzer assembly is configured to require the number of pulses of first light energy in which the pulse maximum of the flash signature is less than a minimum pulse maximum threshold within a specified range of previous pulses to exceed a defined zero pulse count in order to identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 80) 80. The method of claim 79, further comprising tracking a history of all pulses of first light energy directed through the light guide in the first direction to distinguish between the intermittent bubble generation condition, the poor plasma generation condition, and the broken light guide condition. (Appendix 81) 77. The method of claim 76, wherein the measure of signal variability of the flash signature comprises a number of transitions identified in the flash signature. (Appendix 82) 82. The method of claim 81, wherein the optical analyzer assembly can identify the operating state as a Chewback state if the number of transitions in the flash signature is greater than a transition threshold. (Appendix 83) 49. The method of claim 48, wherein directing the pulse of first light energy includes the guide distal end including a distal light receiver, and further includes receiving the second light energy from within the balloon interior using the distal light receiver, the second light energy traveling through the light guide in the second direction. (Appendix 84) 84. The method of claim 83, wherein the step of receiving second light energy includes the second light energy received by the distal light receiver being from ambient light near the guide distal end of the light guide. (Appendix 85) 85. The method of claim 84, wherein the optically analyzing step includes optically analyzing the second light energy using the optical analyzer assembly to determine whether ambient light is collected near the guide distal end of the light guide. (Appendix 86) 86. The method of claim 85, wherein the optically analyzing step includes the optical analyzer assembly including a beam splitter and an imaging device, and further includes the step of receiving the second light energy and directing a portion of the second light energy to the imaging device using the beam splitter. (Appendix 87) 87. The method of claim 86, wherein the optically analyzing step further comprises positioning an optical element along a beam path between the beam splitter and the imaging device, and coupling the portion of the second light energy to the imaging device using the optical element. (Appendix 88) 88. The method of claim 87, wherein the optically analyzing step further includes positioning a second beam splitter along the beam path between the beam splitter and the imaging device, and receiving the second optical energy and directing at least a portion of the portion of the second optical energy onto the imaging device using the second beam splitter. (Appendix 89) 89. The method of any one of claims 86-88, wherein the optically analyzing step further comprises generating a signal using the imaging device based at least in part on ambient light contained in the portion of the second light energy. (Appendix 90) 90. The method of claim 89, wherein the optically analyzing step further includes directing the signal from the imaging device to control electronics to determine whether ambient light is collected near the distal end of the light guide. (Appendix 91) 91. The method of claim 90, wherein the step of directing a signal includes determining by the control electronics that ambient light is collected near the distal end of the light guide is an indication that the catheter system is being used in an improper manner with the balloon not positioned substantially adjacent to the treatment site. (Appendix 92) 92. The method of any one of claims 48 to 91, wherein the step of generating a first light energy includes the light source including a laser. (Appendix 93) 93. The method of any one of claims 48 to 92, wherein the step of generating first light energy includes the light source including an infrared laser that emits the first light energy in the form of pulses of infrared light. (Appendix 94) 94. The method of any one of claims 48 to 93, wherein the step of receiving the first light energy includes the light guide including an optical fiber. (Appendix 95) 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or a heart valve, comprising: a light source that generates a first light energy; a balloon positionable substantially adjacent the treatment site, the balloon having a balloon wall defining a balloon interior, the balloon interior receiving a balloon fluid; a light guide configured to receive the first light energy at a guide proximal end and guide the first light energy in a first direction from the guide proximal end toward a guide distal end positioned within the balloon; an optical analyzer assembly configured to optically analyze second light energy from the light guide traveling in a second direction opposite the first direction, the optical analyzer configured to optically analyze the second light energy to detect an operating condition of the catheter system; and A catheter system comprising: (Appendix 96) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least one of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a plasma failure condition, (v) a light guide breakage condition, and (vi) a chewback condition. (Appendix 97) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least two of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 98) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least three of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a poor plasma generation condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 99) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least four of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 100) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect at least five of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 101) 96. The catheter system of claim 95, wherein the optical analyzer is configured to optically analyze the second light energy to detect each of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide breakage condition; and (vi) a chewback condition. (Appendix 102) 102. The catheter system of any one of claims 96 to 101, wherein the optical analyzer assembly can be further configured to stop operation of the catheter system upon detecting one or more of a poor plasma generation condition, a broken light guide condition, and a chewback condition. (Appendix 103) 103. The catheter system of any one of claims 95 to 102, wherein the first pulse of light energy directed through the light guide in the first direction produces a plasma flash that can be captured by the optical analyzer assembly in the form of a flash signature that can provide an indication of the operating state of the catheter system, the flash signature including summary parameters such as at least one of pulse maximum, rise time, width, onset time relative to a baseline, and a measure of signal variability. (Appendix 104) 104. The catheter system of claim 103, wherein the optical analyzer assembly is capable of identifying the operating condition as a guide distal end plasma initiation condition if the pulse maximum value of the flash signature is greater than a maximum pulse maximum threshold. (Appendix 105) 104. The catheter system of claim 103, wherein the optical analyzer assembly is capable of identifying the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition when the pulse maximum value of the flash signature is less than a minimum pulse maximum threshold. (Appendix 106) 106. The catheter system of claim 105, wherein the optical analyzer assembly is configured to require that the number of pulses of first light energy in which the pulse maximum of the flash signature is less than a minimum pulse maximum threshold within a specified range of previous pulses exceed a defined zero pulse count to identify the operating condition as one of an intermittent gas bubble condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 107) 107. The catheter system of claim 106, wherein a history of all pulses of first light energy directed in the first direction through the light guide is tracked to distinguish between the intermittent bubble generation condition, the poor plasma generation condition, and the light guide damage condition. (Appendix 108) 104. The catheter system of claim 103, wherein the measure of signal variability of the flash signature comprises a number of transitions identified in the flash signature. (Appendix 109) 109. The catheter system of claim 108, wherein the optical analyzer assembly is capable of identifying the operating state as a Chewback state if the number of transitions in the flash signature is greater than a transition threshold. (Appendix 110) 1. A method of treating a treatment site within or adjacent to a blood vessel wall or heart valve, comprising: generating a first light energy using a light source; positioning a balloon substantially adjacent the treatment site, the balloon having a balloon wall defining a balloon interior, the balloon interior receiving a balloon fluid; receiving the first light energy at a guide proximal end of a light guide; guiding the first light energy in a first direction from the guide proximal end toward a guide distal end positioned within the balloon; optically analyzing second light energy from the light guide traveling in a second direction opposite the first direction, wherein an optical analyzer is configured to optically analyze the second light energy to detect an operating condition of the catheter system; A method comprising: (Appendix 111) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least one of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a plasma failure condition, (v) a light guide broken condition, and (vi) a chewback condition. (Appendix 112) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least two of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 113) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least three of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 114) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least four of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 115) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect at least five of: (i) a normal operating condition; (ii) an intermittent bubble generation condition; (iii) a guide distal end plasma initiation condition; (iv) a plasma failure condition; (v) a light guide broken condition; and (vi) a chewback condition. (Appendix 116) 111. The method of claim 110, wherein the optically analyzing step includes optically analyzing the second light energy to detect each of (i) a normal operating condition, (ii) an intermittent bubble generation condition, (iii) a guide distal end plasma initiation condition, (iv) a plasma failure condition, (v) a light guide broken condition, and (vi) a chewback condition. (Appendix 117) 117. The method of any one of claims 111-116, further comprising, upon detecting one or more of a poor plasma generation condition, a broken light guide condition, and a chewback condition, shutting down operation of the catheter system using the optical analyzer assembly. (Appendix 118) 118. The method of any one of claims 110-117, further comprising directing the first pulse of light energy in the first direction through the light guide to generate a plasma flash that can be captured by the optical analyzer assembly in the form of a flash signature that can include summary parameters such as at least one of pulse maximum, rise time, width, onset time relative to a baseline, and a measure of signal variability that can provide an indication of the operational state of the catheter system. (Appendix 119) 19. The method of claim 118, wherein the optical analyzer assembly can identify the operating condition as a guide distal end plasma start condition if the pulse maximum value of the flash signature is greater than a maximum pulse maximum threshold. (Appendix 120) 19. The method of claim 118, wherein if the pulse maximum value of the flash signature is less than a minimum pulse maximum threshold, the optical analyzer assembly can identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 121) 121. The method of claim 120, wherein the optical analyzer assembly is configured to require the number of pulses of first light energy in which the pulse maximum of the flash signature is less than a minimum pulse maximum threshold within a specified range of previous pulses to exceed a defined zero pulse count in order to identify the operating condition as one of an intermittent bubble generation condition, a poor plasma generation condition, and a broken light guide condition. (Appendix 122) 122. The method of claim 121, further comprising tracking a history of all pulses of first light energy directed through the light guide in the first direction to distinguish between the intermittent bubble generation condition, the poor plasma generation condition, and the broken light guide condition. (Appendix 123) 119. The method of claim 118, wherein the measure of signal variability of the flash signature comprises a number of transitions identified in the flash signature. (Appendix 124) 124. The method of claim 123, wherein the optical analyzer assembly can identify the operating state as a Chewback state if the number of transitions in the flash signature is greater than a transition threshold.

Claims

1. 1. A catheter system for treating a treatment site within or adjacent to a blood vessel wall or heart valve, comprising: an energy source configured to generate a first energy and configured to move in a first direction; an optical analyzer configured to receive and optically analyze second energy traveling in a second direction opposite to the first direction, the optical analyzer configured to optically analyze the second energy to detect an operating state of the catheter system.

2. 10. The catheter system of claim 1, wherein the optical analyzer is configured to optically analyze the second energy to detect at least one of a normal operating condition, an intermittent bubble condition, a guide distal end plasma initiation condition, a poor plasma condition, a broken light guide condition, and a chewback condition.

3. 10. The catheter system of claim 1, wherein the optical analyzer is configured to stop operation of the catheter system upon detecting one or more of a poor plasma generation condition, a broken light guide condition, and a chewback condition.

4. 10. The catheter system of claim 1, wherein the first pulse of energy is configured to generate a plasma flash that can be captured by the optical analyzer in the form of a flash signature.

5. The catheter system of claim 4 , wherein the flash signature includes parameters related to the operating state of the catheter system.

6. The catheter system of claim 5 , wherein the parameters include at least one of a pulse maximum, a pulse rise time, a pulse width, a pulse start time, and a variability of the pulse signal.

7. The catheter system of claim 6 , wherein the optical analyzer is configured to identify the operating state based on the pulse maximum of the flash signature being greater than a maximum pulse maximum threshold.

8. The catheter system of claim 7 , wherein the optical analyzer is configured to identify the operating condition based on the pulse maximum of the flash signature being less than a minimum pulse maximum threshold.

9. 9. The catheter system of claim 8, wherein the optical analyzer is configured to compare the number of pulses in the flash signature where the pulse maximum is greater than the maximum pulse maximum threshold with the number of pulses in the flash signature where the pulse maximum is less than the minimum pulse maximum threshold.

10. The catheter system of claim 1 , further comprising a balloon having a balloon wall defining a balloon interior, the balloon interior configured to receive a balloon fluid.

11. The catheter system of claim 10 , wherein the first energy is configured to generate a plasma within the balloon.

12. 12. The catheter system of claim 11, further comprising an energy guide configured to receive the first energy at a guide proximal end and guide the first energy in the first direction from the guide proximal end toward a guide distal end positioned within the balloon interior.

13. 13. The catheter system of claim 12, including a safety shutdown system selectively activated to prevent the first energy from the energy source from being received by the proximal guide end of the energy guide.

14. 13. The catheter system of claim 12, wherein the guide distal end includes a distal receiver that receives the second energy from within the balloon interior, the second energy traveling through the energy guide in the second direction.

15. 15. The catheter system of claim 14, wherein the second energy received by the distal receiver is emitted from the plasma generated in the balloon fluid within the balloon interior.

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